Maintenance suggestions while the AC and coolant systems are open

[MikeSandford]

Did some searching on the forum but I didn't obviously find any threads with suggestions. I did find this maintenance schedule on the million mile sprinter website though. https://millionmilesprinter.com/blogs/news/t1n-maintenance-schedule

Due to my AC being broken from a fan bracket rub-through (https://sprinter-source.com/forums/index.php?threads/144224/) the AC system is currently not charged. And I'm going to have the condenser out while I'm swapping into the new one. While I'm doing that it doesn't seem like a lot of effort to also take the intercooler out and I've already been thinking about flushing the cooling system, so if it's empty it's not a big deal to take the radiator out. That would give me great access to the front of the engine to replace both of the stationary idler pullies and also to replace the tensioner pully and the serpentine belt. With the coolant system open I should probably replace the water pump and the thermostat.

My HPFP leaks a bit until the engine warms up so I need to pull that off and tighten and loctite the bolts which is pretty easy with everything this far apart.

Is there anything else I'm missing? I'm planning on checking on the condition of the harmonic balancer while I'm in there. I know I need to store the radiator fan upright for the viscous clutch. Should I replace the clutch while I'm at it? I regularly see temps over 200 and occasionally over 212 when going uphill and it's hot out.

Also if I'm asking for trouble doing all this or if there are particular pitfalls to avoid I'm all ears. Thanks all!

EDIT: The van has almost 240k on it and it was a business vehicle up until I bought it 2 years ago.

 

[Midwestdrifter]

If the cooling system doesn't have any obvious deposits, I wouldn't bother with a chemical flush.

Cleaning the cooling stack of debris is a good idea if you are in there.

Water pumps typically last about 150k. But idler pulleys and tensioners don't. So I generally suggest doing the water pump, tensioner, pulleys, and checking the alternator overrun clutch at the same time.

HPFP bolts do cause leaking. I would also check the two short rubber hoses that run to the HPFP. They get soft and leak at the clamps with age. If they are original, replace them.

 

[MikeSandford]

If the cooling system doesn't have any obvious deposits, I wouldn't bother with a chemical flush.

Okay that makes sense. I was mostly thinking garden hose flush to try and rinse the old coolant out before I drain it real good and refill with coolant and distilled water.

Cleaning the cooling stack of debris is a good idea if you are in there.

100% agree, was on my mental list but I didn't write it down. Thanks for the reminder!

Water pumps typically last about 150k. But idler pulleys and tensioners don't. So I generally suggest doing the water pump, tensioner, pulleys, and checking the alternator overrun clutch at the same time.

Yup this was on the list. My alternator is new because I wanted more power for charging but I'll double check it while I'm there just in case.

HPFP bolts do cause leaking. I would also check the two short rubber hoses that run to the HPFP. They get soft and leak at the clamps with age. If they are original, replace them.

Good idea on the hoses. I was thinking about ordering those as they're cheap, maybe $12 each on europarts-sd but I forgot until just now. Re-use the clip-clamps or replace with aftermarket machine screw driven clamps?

 

[schwarzwaldsprinter]

If you have everything out, I would replace water pump and thermostat with housing.
Because you have the AC open, I would replace ALL O-Rings for the AC. You can by a full kit from Europarts SD. When I did that I found most of the old o-rings rings were falling apart.
Afterwards, I also charged the system with Nitrogen to 300 PSI to detect a at possible leaks. Leave it in there for a while as You can check the pressure of the system over the Diagnostic. If it holds after driving a bit, then you can bring it somewhere to have the system filled.

 

[MikeSandford]

If you have everything out, I would replace water pump and thermostat with housing.
Because you have the AC open, I would replace ALL O-Rings for the AC. You can by a full kit from Europarts SD. When I did that I found most of the old o-rings rings were falling apart.
Afterwards, I also charged the system with Nitrogen to 300 PSI to detect a at possible leaks. Leave it in there for a while as You can check the pressure of the system over the Diagnostic. If it holds after driving a bit, then you can bring it somewhere to have the system filled.

Great suggestions!

In an older thread (https://sprinter-source.com/forums/index.php?threads/111278/post-1710261) I documented my saga to try and get very solidly cold vent temps from my van. I was seeing 50f at best and I wanted to get closer to 40f as that's extra cooling capacity and I live in the south. I ended up replacing the TXV and the compressor and reverse flushing the evaporator and I got a fair bit of crud and junk out. While I was doing that I replaced all the O-rings except for the ones going to the condenser. Now that I'm working on that I have the remains of the O-ring kit so I'll swap those for sure.

 

[Midwestdrifter]

Okay that makes sense. I was mostly thinking garden hose flush to try and rinse the old coolant out before I drain it real good and refill with coolant and distilled water.

100% agree, was on my mental list but I didn't write it down. Thanks for the reminder!

Yup this was on the list. My alternator is new because I wanted more power for charging but I'll double check it while I'm there just in case.

Good idea on the hoses. I was thinking about ordering those as they're cheap, maybe $12 each on europarts-sd but I forgot until just now. Re-use the clip-clamps or replace with aftermarket machine screw driven clamps?

You can use bulk fuel injection hose, the bends aren't very tight. I suggest good quality fuel injection clamps, as you can tweak them a bit as the hose compresses with age.

Thermostats are a rare failure item, and are designed to fail open. There have been reports that new (including OE) units running a bit hotter, so many folks opt to keep the original units if they aren't leaking.

 

[MikeSandford]

You can use bulk fuel injection hose, the bends aren't very tight. I suggest good quality fuel injection clamps, as you can tweak them a bit as the hose compresses with age.

Thermostats are a rare failure item, and are designed to fail open. There have been reports that new (including OE) units running a bit hotter, so many folks opt to keep the original units if they aren't leaking.

More great points! I already ordered the molded hoses so I'll probably stick with those, but knowing I can keep the same stat is nice.

I have ordered some fuel injection clamps off of Amazon (https://www.amazon.com/Tnisesm-Injection-Assortment-Sleeving-Automotive/dp/B0CTFLDZG3/) but I'd love a suggestion for something better, especially for these clamps that are so hard to get to. Down on the fuel tank or at the fuel filter it's merely annoying to swap them, but at the HPFP it's a real hassle.

 

[marklg]

More great points! I already ordered the molded hoses so I'll probably stick with those, but knowing I can keep the same stat is nice.

I have ordered some fuel injection clamps off of Amazon (https://www.amazon.com/Tnisesm-Injection-Assortment-Sleeving-Automotive/dp/B0CTFLDZG3/) but I'd love a suggestion for something better, especially for these clamps that are so hard to get to. Down on the fuel tank or at the fuel filter it's merely annoying to swap them, but at the HPFP it's a real hassle.

I've gotten stainless steel ones, for not really any good reason as there usually is low humidity and enough oil to coat them to prevent rust. On the fuel filter, they get replaced every 5 times or so.

I even got a lot of assorted hose clip clamp pliers, but those behind the HPFP are really tough.

Regards,

Mark

 

[LowBudgetT1N]

I didn’t see the oil cooler mentioned but I’d replace that too while everything is apart.

 

[Midwestdrifter]

I didn’t see the oil cooler mentioned but I’d replace that too while everything is apart.

At least the seal. Access isn't much better with radiator off.

 

[3Play]

Good time to cut your fan shroud in half horizontally and add locating tabs, so you can pull the top half without having to take the fan out, or tilt the cooling pack the next time you need access.
Also, I took out all the reverse torx bolts on the front cover that had anything to do with replacing parts, like the belt tensioner.
And I replaced them with Allen headed cap screws which will retain a wrench when you let go of it.
Those reverse torx are the bane of the universe and nearly impossible to hold a socket on when fishing in cramped spaces, like the tensioner, behind the radiator......

 

[MikeSandford]

Good time to cut your fan shroud in half horizontally and add locating tabs, so you can pull the top half without having to take the fan out, or tilt the cooling pack the next time you need access.
Also, I took out all the reverse torx bolts on the front cover that had anything to do with replacing parts, like the belt tensioner.
And I replaced them with Allen headed cap screws which will retain a wrench when you let go of it.
Those reverse torx are the bane of the universe and nearly impossible to hold a socket on when fishing in cramped spaces, like the tensioner, behind the radiator......

I found a post where you show some pictures of how to do this, which is great. https://sprinter-source.com/forums/index.php?threads/123623/post-1472352 It looks like some pieces of aluminum riveted to the shroud. Do you put the pieces of flat bar on both the inside and the outside? Or just the outside? Would love to get some more details so I don't have to think it through too hard. Or a link to an existing post if you've already detailed it. Thanks!

 

[3Play]

I found a post where you show some pictures of how to do this, which is great. https://sprinter-source.com/forums/index.php?threads/123623/post-1472352 It looks like some pieces of aluminum riveted to the shroud. Do you put the pieces of flat bar on both the inside and the outside? Or just the outside? Would love to get some more details so I don't have to think it through too hard. Or a link to an existing post if you've already detailed it. Thanks!

Yes, both sides of either the top, or bottom half of the shroud. it needs to locate and trap the side without the flat stock.
This really saves effort the next time you need to do anything behind the shroud. Hot rodders have been doing it for decades......

 

[MikeSandford]

Well with a bit of effort here and there over a couple of days I'm all the way in to the front cover of the engine!

A few tricks:
1. get a box of "rubber end caps" on amazon to cap any lines and keep trash out of the transmission, power steering, etc (https://www.amazon.com/dp/B09F33RCXT)
2. the radiator coolant outlet is on the side of the radiator not the back, you can see it clearly with the driver's headlight out
3. disconnect the power steering cooler/return line at the pump reservoir and immediately cap it to avoid draining the system, then you can mess with the other end without siphoning it empty
4. an impact can help you get the fan clutch off without having to invent a tool or a clamp or whatever

I'm still waiting on all of my parts to arrive but today the plan is to try and get the HPFP off and loctite the screws and get it back on the van. Hopefully that'll go easy but since I don't have the water pump and everything else yet if something doesn't come loose easily I can afford to work on it at a relaxed pace.

 

[MikeSandford]

While doing some other things I noticed that the rubber hose in the discharge line from the compressor had a nick in it. Based on the size of the nick and the slowness of the leak I think it's just in the outer covering but I've ordered a new one anyhow. When a system charge is $20-$30 worth of refrigerant it seems kind of silly to not spend that much on a new undamaged hose. I sure do wish it were possible to know if the replacement is as high quality as the original as I'm always slightly suspicious but I figure something new even if slightly lower quality is probably better than 20 years old.

 

[Midwestdrifter]

FYI aftermarket compressor discharge lines are aluminum. The factory is steel. They may need tweaking to fit, and they may fatigue crack at the bolted bracket after a while (years probably).

The AC hoses are typically fine unless the fiber cords are visible and damaged.

 

[MikeSandford]

Well I got the high pressure fuel pump (HPFP) off of the front of the van, got it all cleaned up and then took the bolts out one-by-one and cleaned them up and loctite'd them and put them back in. Crossing my fingers I did everything right. I used lots more of my rubber end caps to keep all barbs clean while I was working.

One thing I noticed is that if you take 3 E10 bolts off of the fuel hard lines right next to the HPFP they can move quite a bit. This was vital for me to be able to get all the old clip-clamps and hoses off and to put the new hoses and bolt clamps on. I tightened everything down what I hope is the right amount but if I ever need to tighten up the rear clamps I think I'm going to have to move stuff pretty far. There's very, very little access. At least with the bolt clamps I don't need to try and get the pliers in there.

Next up is the water pump but I'm taking a little break first. I ordered a gates before I saw all the posts about buying the mercedes branded one. But I also read the posts that talked about making sure you have metal gaskets. The gates pump has a metal seal off on the side, but a felt/paper/composite main gasket. I figured that out somehow before it arrived, so I ended up ordering 2x of the elring main pump gaskets off of rockauto so I'm hoping that all works right and I don't need to RTV them. I'll be pretty annoyed if I get this thing all back together and it leaks somewhere.

Knowing a leak is possible I think I'm going to reassemble everything but the AC and do a bit of driving and get a couple of heat cycles on it before I put everything fully back together. I don't want to vaccum it out good and throw a charge in the system just to have to take it all apart again due to a leak.

 

[MikeSandford]

I got all of the non-AC stuff put back together yesterday and even got the van started once. I didn't see any obvious water pump leaks nor the cold-engine-diesel-leak I had previously experienced, at least on that one start. I got my shroud cut in half as suggested by 3play and I'm working on the AC right now.

I had it on the vacuum pump overnight and still wasn't seeing great micron numbers but I think that might be due to the schrader ports leaking. I did put some plumbers pipe dope on the threads of the pipe connection at the condenser not to seal it but to make it easier to take apart in the future. I'm hoping I never need to but if I do, it's there.

 

[MikeSandford]

Got a couple of drives in and everything seems to be holding together. I forgot to burp it before driving so I had to stop and add water to the coolant tank 2-3 times on the first drive which was silly of me. I'm also finding that my heater valve isn't as reliable as it used to be and I'm getting heat sometimes when I want AC. This used to happen maybe once every few months. Hopefully after a few more drives it'll calm down again.

I did use permatex high tack gasket sealant when I bolted the water pump output hose onto the new pump and also when I put the new pump in. It was a bit of a hassle as it's pretty sticky but I really, really didn't want anything to leak.

She doesn't seem to be leaking diesel anymore either up front or from the tank or the cooler or anywhere, knock on wood. I'm hoping that my mini overhaul will keep the gremlins at bay for a while.

I did notice that my ribbed idler was still spinning but essentially dry as it has almost no bearing resistance. I'm glad I got that before it seized up and shredded a belt.

 

[MikeSandford]

Everything still seems to be going OK. I've added a full quart of transmission fluid as some definitely leaked during the service. I guess it was low to begin with. There was a bit of slipping when cold and that's gone and any rumble strip noise (RSN) I was experiencing is significantly reduced.

I think I'm going to do a full transmission service soon. I also need to work on the diesel heater and while I'm doing that I'll probably do a coolant flush. What came out was pink/red and that could be to spec or it might not be. I'm not entirely sure. It did look pretty clean so I'm not super worried but it would be nice to get everything on a known service interval.