Cooling System Leak Diagnosis

A real-world example of something I was trained to do at school is leak diagnosis using air pressure and soapy water. The potentially leaking system is pressurized with a manual air pump or with compressed air with a regulator to control specific pressure, and soapy water is sprayed on any potential areas where the leak could be. Radiators, charge air coolers, fittings, sealed connections, hose and line ends, are the primary culprits. That does not exclude hoses or lines themselves as they might have holes enough to cause a leak. We have done this in the school shop on things like the Charge Air Cooler on a Series 60 to find the source of a leak.

So, back to the real world example. I changed the water pump on a Duramax (more on that in another post), and after completing the installation found that the system held neither vacuum nor pressure. I pressurized the cooling system to 15 psi and sprayed soapy water all over. Eventually, I heard a fizzing sound. Crawling under the truck, I noticed that a pipe that enters the rear of the water pump was foaming quite heavily. The source of our leak. This connection has a simple dry non-metal gasket.

Off came the water pump again, and inspection of the flanges (which were straight-edged) and gasket gave no obvious hints as to why they would be leaking. I put a special silicone sealant on the gasket, reinstalled the water pump and pressurized and tested the system the following morning with no obvious signs of our leak.

Soapy water tells us where the leak is located.

Evidence of the leak on the gasket.

Reflection:

Sometimes the root cause of the problem is not entirely obvious, even when you have located and inspected where the problem occurs. Using a silicone sealer solved the leak, and we will have to leave it at that. I don't have the answer to this one, but in the end the fix was simple. Perhaps others have possible insight into the root cause? Curious minds would like to know, if so.

Wire Repair

Apologies for the lack of updates on the blog since graduation, illness and work have kept me exhausted. As my former energy and enthusiasm returns, I will make at least weekly updates henceforth.

I have done many things since my last post, ranging from oil changes and fuel filters to basic scan tool work and injector replacement, electrical diagnostics, and more additions to my toolbox. As I am several weeks behind, rather than writing it all up as one or several posts of my weekly activities, I will present them as single activities per post mixed among my current work. Such as a new tool, or the injector replacement.

For today's topic and what I did at work today: wire repair. A Volvo dump truck which had multiple wiring issues involving missing or damaged insulation, and a toggle switch which needed replacement.

Damaged insulation at the toggle switch terminals.

New toggle switch and a choice of two heat-shrink crimp connectors.

I chose the red, smaller one suitable for 16 gauge wire. This is the finished product, before putting the switch in its mounting and testing to ensure the lights it controls work. They did.

Connecting a fresh piece of wire to replace a damaged section. Again, heat-shrink connectors were used.

My reflection:

I am starting to get decent at basic wire repairs. I prefer the use of heat-shrink connectors, but they are not always necessary (in the cab, for instance). In my learning process, I have trashed a few of these crimp connectors as my crimping tool (Snap-On brand) can punch through their insulation if you're not careful. My final attempt in the last picture had zero connector casualties and no mistakes, as I am getting a decent feel for the crimping process. Third attempt at wire repair, third time is the charm?

Finals

This week was our final exam for Electronic Diesel Engine Controls. Heavy emphasis on the test was put on use of electronic service information, wiring diagrams, and using a scan tool in conjunction with service information to troubleshoot sensor and wiring problems.

Late-model Freightliner Coronado, used to pull a code for bad turbo intake sensor for our final exam. Our teacher had simply unplugged the sensor.

Reflection:

With finals over, it gives a lot of time to reflect on all the lessons learned and experiences had over my 3 years in the Auto-Diesel shop. My education was not just a matter of learning how to wrench on vehicles. It was learning how to be confident in my abilities and get engaged, even if I make mistakes. It was about interacting with and getting along with my class mates, my teachers, and potential customers. It was about building a pathway to my career.

What is next for me? Tomorrow I go full time at my current place of employment, and say good bye to the Auto/Diesel shop which I have called home for 3 years. This isn't the end, it is just the beginning. I will stop by whenever time permits to see how the place where I got my start is doing, and I will keep my instructors informed of my activities in the Automotive/Diesel Truck world on a regular basis.

It has been, quite an experience!

GMC Sierra 5.3L Final Assembly

This week in class, with permission from my instructor Jeffrey Starkey, my team worked on my GMC Sierra 1500, which was in the shop for repairs originally as part of another class which I helped with. It has a 5.3L gasoline engine, but for the purposes of our class it is very much "electronic engine controls," even if not a diesel. It had been my hope to get the truck finished that day and pulled out of the shop.

Most of the engine work had been done, all that needed to be finished on it was valve covers, the radiator fan, coolant hoses, and of course... electrical connections to sensors and other electrical components. Final step was engine oil and coolant (which we used water to flush the system).

We got everything hooked up and started the truck. Whoops! Coolant leaks everywhere, and a bad idle. What did we do wrong?

This engine has four blocks with little nipples that go into coolant passages on the heads, two on front and two in back. The front ones are passages for the "coolant air bleed pipe" which connects under the throttle plate to the intake and allows air to bleed out of the cooling system. The rear two are simply there to block the flow of coolant out of the heads.

In my haste to get this vehicle finished, I had put the gaskets to these on wrong, and coolant was leaking out of all 4. Lesson learned! We luckily just had to take them back off, put the gaskets on correctly, and we also put some RTV silicone on them just to be sure of correct sealing.

I drove the truck onto our alignment rack, and found it died on me several times. On Thursday, we found this was due to the MAP sensor not being plugged in.

On Thursday, we fixed these issues and finally got the truck running decently and pulled out of the shop.

First ignition after we fixed the leaks and the MAP sensor was plugged in.

Reflection:

Don't get in a hurry. It's not a race. Take the time to go through your work and ensure it is all correct and up to spec. I made some mistakes through being in a rush and learned well from those lessons

The truck still has some issues which need to be ironed out, such as a misfire. However the big work is done. Just a matter of working out the kinks that were probably not related altogether with the crack in the head we fixed, and as always the learning will continue.

Series 60 Crank/No-Start Diagnosis

This week since my team was absent, I was asked to help a member of another team finish diagnosing a Series 60 with a Crank/No-Start condition. We had a clear hose hooked up from the fuel filter to the transfer pump, which I noticed at starting had little more than air in it.

We also noticed that the filter itself had no fuel, so we put fuel in it and tried starting it again. We found air bubbles forming in the (clear) filter housing. After referring to service literature we found this meant an air leak anywhere between the fuel tank and fuel filter, with perhaps defective housing o-rings. Fuel is sent to the transfer pump past the filter.

Checking, we found one o-ring missing from the small fill cap at the top of the filter. We replaced this. Upon startup, we made more progress but we still had significant problems and the truck would not start.

So I crawled under the truck and started at the fuel tanks tracing the lines back. And this is what I found:

Each line comes in from the fuel tanks to this fitting, and goes out to the fuel filter from there.

At first I noticed a wet spot on the fitting, and after touching it found the line to be loose. I tightened it up and we tried again. This time, we got the truck to start.

Reflection:

Problems can have more than one cause. In our case, and agreeing with our service information, there were 2 causes of this no-start condition and we could not get the truck to start until we fixed both of them.

It made sense to get under the truck and inspect the lines and fittings going to the filter, especially after replacing the missing o-ring did not fix the problem. After we had made sure all was okay, we could verify our fix and move, if necessary, to the next step of diagnosis if we still have issues.

Oil Pressure Sensor Circuit Fault, Code 141 (Cummins N14 Celect Plus)

This week in the shop we did some cleanup. Pretty standard stuff, but while looking for a magnet I found this:

Mechanic ingenuity?

Someone had welded a socket to a long piece of all-thread. What the purpose of this tool was I did not learn.

What I did learn, however, was how to read flash codes on a Cummins N14 Celect Plus in the school's International sleeper truck. Courtesy of some quick research on Cummins Quickserve and Google, we ascertained exactly how to read the code flashed on the dash, and found one code, 141. Once again with the help of Google we found this to be an oil pressure sensor circuit fault. So we printed out a component location diagram and went to look:

Oil pressure sensor location. Right under the ECM on the driver's side, mounted in the block.

The actual sensor on the vehicle.

When we checked the sensor, it was unplugged. Mistake from a previous team? Deliberate bugging? Who knows, but once we plugged the sensor back in, the check engine light went out and we were good to go.

Reflection:

Once again we get back to "keep it simple, stupid," the sensor was simply unplugged. However, that might not have been the only problem with it. So what is the next step in the repair process? Verify that the seemingly obvious fix did indeed correct the problem. In our case, it did. But what if there were wiring issues down the line? Then the diagnostic process would continue, with one possible cause (disconnected connector) eliminated. That would have been our next step, had the check engine light stayed illuminated.

The Importance of Maintenance

This week, due to class cancellations, I will briefly post on something I did at work.

While working on a truck for another issue, it was necessary to unhook the batteries. Part of "modus operandi" where I work is to clean pretty much everything we remove if we are putting the same parts back on. So while I had the battery cables disconnected, I went through all the terminals and cable ends and cleaned them all up. Here is what I found on some of them:

I bead-blasted the cable ends and cleaned the nuts for the terminals up on a wire wheel. We had to replace one cable end because it was so badly corroded.

Reflection:

It's good practice to get into the habit of routinely checking and cleaning things such as battery cables and terminals, especially if you have to disconnect them to work on something else anyway. I routinely clean any electrical connections such as this whenever I have them off. It may take an extra minute or two, but it helps to solve a lot of avoidable electrical problems which are the result of the "green" corrosion pictured above.

Rigging A Rig

This week in class my team was responsible for rigging several different engines to have "issues." It is the responsibility of the other teams to successfully diagnose those issues and get them running again. All of these engines were confirmed to run before we rigged them.

Cleaning up the Jake brake connectors on our Series 60 dyno engine, as the engine brakes will not be put back on for now.

Another interesting development of the week was an in-class presentation. No, I don't mean power point slides. The team working on the no-start condition experienced by the Series 60 in the FLD Freightliner was asked to present their findings, in their own words, to the instructor and the rest of class. So far we have determined that the starter relay may have an issue, and they swapped another one in.

I removed this starter relay off one of our stand-engines for the other team to put on the FLD.

This engine started, but now won't. I wonder why? Well, that is for the next team to figure out.

Finally we hooked up a clear plastic hose between the fuel filter and the transfer pump.

Why would we do this? What don't we want in the fuel system after the filter? This is for the next team to answer, or perhaps a class demonstration.

Reflection:

Instead of solving problems, my team has been causing them. But we did not just rip and tear, we strategically bugged these engines. In order to do that, we need just as much understanding of the system's operation as a technician fixing the problem would.

We could fix what we broke in a few short minutes, but it may take another team 30 minutes or an hour or more to even find where the problem is.

Diagnostic time, that is finding where the problem is in the first place, can be the vast majority of the time it takes for a repair. The actual fixing, part replacement, etc. etc. can be a tiny fraction of the work done.

Capstone Project

Background In Mechanics

For the capstone project, it was requested that I provide a little background of how I ended up where I am, and what experiences I've had working in the real world among other things.

To start off, I had never worked on vehicles before my decision to go to school for it. I originally went to school and trained to be an electrician, and it was only after working in the field did I realize it wasn't for me. A morbid fear of heights, coupled with a lack of any serious passion for the field, left me wanting to change direction while I still had the opportunity.

So I researched several different career paths to suit my needs, and the one that struck me immediately was being a mechanic. I researched the field more, including expected income and job descriptions. I watched YouTube videos of people like EricTheCarGuy. Finally, I made the decision to enroll in the WSCC Automotive/Diesel Truck program. The rest is history, as I have been there for 3 years and am set to graduate with Associate's degrees in Automotive Service Technology and Diesel Truck Systems.


Working In The Field


I have been employed by an independent automotive and truck repair shop now for about two and a half months. We work on everything from cars to class-8 trucks, everything from brake service and oil changes to engine swaps and rebuilds, diagnostics and driveability issues. Below are a few pictures of projects we've been working on recently or currently working on.

International 9200i. Earlier that day we had everything up to the gear housing off to fix a leak.

Transfer case my boss is working on off another truck.

Still waiting on the turbo for the 9200i, which is being replaced.

Cleaning up ground terminals with emery cloth before hooking them back up to the radiator support.

About to replace the park brake valve on a Chevy single-axle dump truck.

 

The new valve installed with compression fittings. The trailer valve was removed as the customer will not be pulling a trailer with this truck.

As you can see, there's a wide variety of work we do. The opportunities to learn something are there on a daily basis.


Tool Selection

Something that has been of particular interest to me since gaining employment in the field is tools. Our shop is visited by S&K and Snap-On tool trucks.

I picked this up from an auto parts store for $5.

The above pictured tool measures bolt and nut sizes on any standard 6-point head in both standard and metric. Until my ability to tell bolt size at a glance gets better, this tool has become a huge time-saver.

My first major tool investment, a set of Grey Pneumatic Duo-Sockets in 3/8" drive. I also bought a 1/4" set. Thinner than regular impacts, they are made and warrantied for use an air impact tools.

My tool purchases have been heavily influenced by what I need on a daily basis. Better lighting, sockets, ratchets, wrenches, are among my first purchases. Tools that come in handy or I tend to borrow from my co-workers a lot are also on the list as I build my toolbox up.

I had these before I started my job, punches and chisels are something I use all the time.

Other good examples of tools I would have or get sooner rather than later are pry bars, flat head screwdrivers, scrapers, hammers, extensions and swivel sockets. The list could go on. All based on what I find myself needing in the shop on a daily basis.

Cummins ISB, Series 60 Dyno Engine, Freightliner Coronado

This week we brought a Cummins ISB down from the upper floor, and it was my team's task to see if it would start, and if not, why not. According to our instructor, this engine has not been started once in the last 4 years.

It is good practice to check fluids before starting any engine or transmission that has been worked on, ESPECIALLY by another person. I was told by a classmate that the fluids were good, however I think back to my instructor's words of wisdom "verify, then trust." I have seen this in action in the real world, I think a good habit to get into.

Cummins ISB, 5.9L diesel. On the battery charger, fluids checked, ready to start - hopefully.

With the fluids good, diesel in the fuel tank, a battery charger on the battery, I turned the key. Nothing. We hooked up a second battery in parallel, which doubles amperage but gives us the same cranking voltage. Turn the key, it cranks but barely. We left it to charge for 10 minutes. Cranking improved but only marginally. We attempted to connect diagnostic scan tools to it (notably Cummins Insite) but had technical difficulties with our software. We did manage to hook up a different scan tool and pulled all active engines codes of which there were 3. Stay tuned next week as we progress on this project.

So we moved on to our Series 60 Dyno Engine, which has recently been made to run. We started her up for a minute or two. However, we are unsure about the lubrication and requirements of this old dyno that hasn't seen action in years, so for now I was instructed to remove the driveshaft so we could run the engine without the actual dynamometer hooked up. So what did I find?

Never worked on this kind of yoke before. Time to learn something new?

I have experience with half-round and full-round driveshaft yokes, but not this kind. The u-joint is held in with snap-rings, and I am still not entirely sure I had to unbolt the yoke "strap" part at all. Due to the awkward position of the snap-rings I needed to remove, and the inability to turn the driveshaft like I would working on a truck, I had access issues to one of the snap-rings.

These pliers were a huge help with solving my accessibility issue. I have made note, and will likely be seeking to add a pair to my own toolbox in the future.

 I was successful in removing the snap-rings, but it was time to clean up and head home before I could make any further progress.

Finally, and a bit out of order as this was pulled in before anything I have just written about, we got a chance to take a closer look at a brand new Freightliner Coronado on loan to us from Matheny Truck Center. It was the task of another team to do an inspection on this vehicle.

If only I could work on trucks this clean.

My reflection:

In addition to all that I have just written about, we also had our midterm to take first-thing in class. A busy day, for sure! Multitasking is yet another skill a good mechanic needs to be able to do. Whether we have multiple projects going on at the same time, or quickly switch from one to the next. This is a lesson I have learned working at a real shop as well. This is simply another reason why organization of parts and tools is so important, as we try to seamlessly move between projects. Paperwork and documentation also plays an important role here.

Series 60 Coolant Level Fault

This week on the Series 60 we had a Coolant Level Low fault to fix. This code was set last week when we tried to get it running after refilling it with the coolant we drained. The system uses a coolant level sensor in the fill tank on top of the radiator.

Active fault code for Coolant Level set by the ECM, as shown on the scan tool.

Our first task after retrieving the code off the ECM was to refer to Detroit Diesel's Power Service Literature to find out what exactly this code means and what procedures are recommended for troubleshooting.

Looking up service literature for this fault code.

Detroit Diesel recommends ensuring that coolant level is actually correct first.

Coolant fill tank on top of radiator, with coolant level sensor right above the radiator fan.

What we found after taking the pressure cap off was the coolant was indeed low. It took almost 2 gallons to fill it up to the correct level where we could see it in the tank with a flashlight.

No more coolant fault code.

The service literature says that following this procedure, the fault code should no longer be set. Of course, we cleared the rest of the codes manually, but there was no active fault for coolant level after we put the scan tool back on the truck.

My reflection:

It's not always a bad sensor or faulty wiring that can set a fault or cause a problem. Sometimes it's the simplest solution that is the correct one. So here our first question for a "coolant level low" fault on a truck should be, "does it actually have enough coolant in it?" And our first action should be to check that it does.

Sometimes it's best not to overthink things and keep it simple.

Sensors & Scan Tools

This week we finished testing the list of 5 sensor we were given to remove and test. Among the list:

1. Thermistor.
2. Pulse generator.
3. Variable-capacitance pressure sensor.
4. Piezo-resistive pressure sensor.
5. Potentiometer. 

The first 4 we tested off a Series 60, and the last one, for ease of access, we tested off a running stand-engine, a Cummins ISX 600.

Test procedures vary for these sensors as they operate on different principles, but the similarities all these sensors share is that they are designed to send a voltage signal back to the ECM to let it determine engine operating conditions. This information can then be used to adjust output parameters such as fuel injection timing, or used as fault detection for driver warning systems.

We also broke out the scan tool and used it to help test these sensors. A multimeter works just as well, but a scan tool can be faster and easier. For instance, we hooked up a gauge and pressure booster to the manifold boost pressure sensor, and with it connected to the ECM and the scan tool hooked up to the truck, we were able to match boost pressure in PSI on the pressure gauge and on the scan tool. This tells us the sensor is good and working as intended.

This could also be done with a multimeter, but would specifications telling us how to interpret voltage readings to a corresponding pressure value.

Applying pressure to the manifold boost pressure sensor with our pressure gauge.

Scan tool data from the ECM match our pressure gauge readings, indicating that the sensor is working as intended.

My reflection:

Not all these tests went flawlessly. We had some technical difficulties involving a crankshaft position sensor, which would not produce voltage when a magnet or piece of metal was passed across it, and a throttle position sensor which gave us readings in reverse of what we expected from specifications. We will likely be revisiting these next class.

The question I might raise then is how would a technician in the field deal with these technical difficulties? How would their methods differ from ours? Did we perhaps make a mistake in our tests, or is there an actual technical problem with the sensors, electrical systems, or tools we were using to test them?

Crankshaft Position Sensor

This week we moved on to "pulse generator" sensors. These include wheel speed sensors for ABS, crankshaft position sensors, and camshaft position sensors.

For ease of removal on the Series 60, we chose the crankshaft position sensor. It is simply bolted to the bottom of the block and works by creating a magnetic field as the crankshaft gear turns, sending voltage signals back to the ECM. A missing tooth is used to tell the ECM engine position.

Crankshaft position sensor prior to removal.

Crankshaft position sensor after removal.

My reflection:

We did not get to test this sensor yet, however it can be tested by putting a multimeter across the electrical terminals and reading voltage as a magnet is passed over it. Failure of this sensor could result in a cranking, no-start condition.

Worth noting on this sensor was how difficult it was to remove due to the fact that the O-ring had swelled up. It took a fair bit of prying and pulling to get this thing out of the engine. Just another testament to the fact that when working with vehicles... it's hardly ever as simple and straight-forward as the textbook says!

Is it -40F or 250F? The ECM can't tell!

This week we took our coolant temperature sensor and heated it in boiling water with our ohmmeter on the electrical part of the sensor. As the sensor's temperature increased, the resistance values went down. From around 3k (3000) ohms resistance at ambient temperature, it fell to just 300 ohms at close to 212F. The sensor is working as intended.

Next we backprobed the electrical connector which runs from the ECM to the sensor and hooked up a variable resistor. At this point, the truck has no coolant in it, the engine is stone cold and not running. We turn the key on and hook up a scan tool to the truck, going to the data stream where we can look at what the coolant temperature sensor is doing.

With resistance set low, the temperature gauge on the dash of the truck is redlined at 250F, matching what the scan tool data stream reads. The truck's ECM thinks the truck is overheating, though in reality the engine is cold. As resistance is increased, the temperature goes down on the dash gauge and on the scan tool data stream. We can make the truck think it's -40F when in reality it's the middle of summer.

Variable resistor backprobing the ECT sensor's connector.

Variable resistor. With this we can lie to the ECM and make it believe the engine is overheating when in reality it's not even running.

The engine is not running, but the ECM believes it's overheating.

Scan tool data showing what the ECM sees. Hmm interesting to note EGR temperature is -40F?

My reflection:

A modern vehicle uses a wide variety of inputs from sensors all around the vehicle, including engine sensors, transmission sensors, wheel speed sensors for ABS and traction control, the list goes on. It uses these inputs to determine the current operating conditions and tweak as necessary for optimum performance. If any of these sensors is faulty or otherwise giving incorrect information back to the ECM, the ECM will act accordingly.

For instance, if the ECT is faulty and giving incorrect information, similarly to how we lied to it with our variable resistor, the truck may be going down the road and think it is overheating when in reality it is just fine. Most modern trucks today would respond to this by derating the engine and forcing the driver to pull over and shut down to prevent damage. All because a sensor or its wiring was faulty.

The primary lesson to be learned here? Modern technicians will have to understand how these sensors work, as well as the electronic and electrical systems they are incorporated into. Without that knowledge, we cannot properly diagnose a fault with these systems.

Engine Coolant Temperature Sensor

This week we pulled the engine coolant temperature sensor off the Series 60. It is located on the right side (passenger) toward the rear of the head and block. It is an NTC-type thermistor which measures engine coolant temperature by changing resistance (temperature goes up, resistance goes down) and sends a voltage signal back to the ECM, which uses the information, along with that from other sensors, to adjust to a wide variety of engine operating conditions.

The sensor can be tested by comparing ambient temperature to resistance. One could also heat up a small container of water, stick the sensor in and measure resistance as long as the temperature of the water is known.

Coolant temp sensor and specifications for temperature and resistance.

Coolant temp sensor.

My reflection:

Removal and testing of this sensor shouldn't be any big deal on a typical engine, what might present a problem is finding specifications for it. It took longer to find specifications (appreciation to our instructor for finding the correct ones) than it did to pull the sensor and make measurements.

The moral here? Sometimes the hardest part of the job isn't turning a wrench, it's finding information! Without information, we would have little idea what correct resistance values are at what temperatures, and be unable to reliably diagnose this sensor.

Organization & Cleanliness

They say that "cleanliness is next to godliness." This week our Electronic Diesel Engine Controls class was cancelled to due illness, so I will use this week's blog post to focus on a general issue which may be a problem for some automotive and diesel shops.

If you were to walk into our shop right now, you might find things like this:

I don't think this is where we put the grease gun after use.

This is just sloppy and unprofessional.

My reflection:


Without an organized shop, tools will be harder to find, may end up lost, stolen, or even present a tripping or other hazard if left on the floor. Leaving tools where it is most convenient instead of where they belong after use is lazy and unprofessional.

Cleaning up messes is part of the job. Oil, coolant, and other fluid spills are not only an inconvenient mess, they are a safety hazard. Clean them up ASAP! This means more than throwing floor dry on it and driving off.

Finally, does leaving trash laying around everywhere really need an explanation?

It reflects poorly on the professionalism of a shop and the character of its technicians when they cannot be organized, clean up messes, or even clean up their own trash. It would be the first and last time I would ever let a shop work on my vehicle where the technicians used it as a coffee table.

Thermostat Housing On The Series 60

This week my team was assigned to work on the FLD Freightliner which has a Series 60 engine in it. Our first task was the testing of various sensors, starting with the engine coolant temperature sensor. This meant draining the coolant and pulling the thermostat housing off the engine.

The coolant is drained either at the driver's side radiator drain valve on the bottom side of the radiator, or a drain plug on the bottom radiator pipe. We drained it at the latter, and my suggestion if draining it here is to wear safety glasses and be ready to get out from under the truck quickly as it will pour out fairly violently. Coolant doesn't taste very good, for the record.

Next we began pulling hoses off the thermostat housing. There is one hose which goes to the upper radiator, another which goes in the side of the thermostat housing from the water pump, and another small hose with a 14mm fitting that runs out from the top to a fitting on top of the radiator.

A lot of hoses and pipes!

Drain pans, not a very good picture. That tire step makes climbing up on the truck easy!

Thermostat housing with the upper radiator hose removed. Note heat shrink clamps, this is the first time I encountered one.

My reflection:

I have worked on this engine before but one thing that struck me was the replacement of the old, often-seen worm and spring clamps with a new heat shrink type. I had never encountered this type of clamp before. To remove them you have to heat them up with a heat gun and cut them off with a knife.

These clamps, although not reuseable, are supposed have a better clamping force than traditional clamps. Will we perhaps see more and more of these on newer trucks and use them as replacements whenever we work on the hoses of older trucks using traditional clamps? Time will tell, but I definitely learned something new this week!