An idea on how to flush the cooling system

[iplagolf]

Hello…I read all that Clark's has about it. Not really a flush but more of how to drain. I have oil in the system from bad oil cooler gaskets. After just draining the radiator and expansion tank, looks to be quite a bit. Searched the archives and found a good cleaning solution of TSP and a pinch of Dawn Liquid. My idea is to fit the upper radiator hose that goes to the block with a male garden size hose fitting. With a sump pump that has a short garden hose attached, attach that hose to the upper fitting. Place the sump pump in a container with hot water and the solution. Have the lower radiator hose dumping into the container with the sump and solution. Circulate until dirty, change solution until circulation runs clean and then flush with clean clear water until no soap or suds. I'll do the same thing to the radiator. The expansion tank can be done the same way. After re-reading this I will remove the thermostat for an unobstructed flow. One question, do I want to do the flush before or after I change the oil cooler gaskets or does it matter? Any input or better ideas would be much appreciated. Fritz

[simssj]

I like your idea about externally recirculating to flush the block with a sump pump and (I assume) a five-gallon bucket of cleaning solution. (Don't forget to open the heater when you do it to flush out any nasties in the heater core!)

If I were doing it, I'd replace the oil cooler gaskets first. (This is a job I need to get to to stop a frustrating oil-leak around the oil cooler housing that I've been putting off. I don't have internal mixing of coolant and oil, but it's just a matter of time, and I'm going to use your technique when I get to that project this winter.

Any particular reason you plan to do the radiator in a separate step from the block? It would seem possible to jury-rig some way to flush them both in a single "wash cycle" with a little creative plumbing.

Also, you might want to think about some way to warm the water a little. Seems intuitive that warmer water is gonna de-gunk the innards a lot quicker.

[iplagolf]

Steve…Thanks for the reminder about the heater core. That's why I posted this. I got the gaskets yesterday from Pelican, I believe I'll change them today. My thoughts on doing the block, radiator and expansion tank separately was to minimize water volume and not spread dirtier areas into cleaner areas, if that is even the case. I have hot water at the garage to use for the solution. Now that I'm thinking about this more, I could pump the solution in from the bottom hose fitting on the radiator through the radiator into the block and out of the bottom of the block back into the solution tank (holder). I will have to do the expansion tank separately because it is only one way in/one way out. Thanks for the input! Fritz

[John_AZ]

If you flush with the old seals in place, you may introduce more oil in the cooling system.

Hints:
Be sure to remove the rear drain plug on the engine below the cam housing. Flush at least twice.
Since you said there was quite a bit of oil--run a rag through all big hoses.
Turn on the heater control to FULL
Test the oil cooler for leaks. mytrplseven did a DIY tester--easy to build.
The oil cooler seals are probably what failed. Clean the engine hole carefully.
The oil cooler seals big green 2 seals must be pre oiled on installation or they will "roll" and fail

Do you have the upgraded 1 piece OPRV or the OEM 3 piece?

You mentioned you plan to make your OPRV alignment tool. It is the top tool shown in the photo for the early cars '85/1. I can get a couple of dimensions if you need them.



GL
J_AZ

[John_AZ]

Change the heater control valve if you see a white deposit --it will drip on the clutch.
Get short hoses it connects to top of engine.
Get the short hose from the WP to the hard line above the WP
The hose frequently "never" changed is the reservoir to the radiator hose. It is the forgotten hose.

and on and on....

J_AZ

[iplagolf]

John…Gasket set # 944-107-147-99 One large metal w/green raised gasket, 2 shims, 2 o-rings, nylon washer and a thick black washer. Going out now to pull the cooler off. I stopped by a mechanic's place this morning to see if he had an alignment tool. He did not, if I could get the dimensions from you I'd appreciate it. I'll post back when it's off the car. Fritz

[simssj]

Fritz; Two things....

One: Please let me know how big a pain in the rump it is to pull the oil cooler cover and replace the gaskets. Are you doing it with the exhaust header in-situ? I've got a drip down there and I've put off doing the gaskets because I dread getting the headers off after 27 years without busting the studs.

Two: Somewhere in the forum is a thread that describes a trick to re-install the OPRV without the tool. Something amount mounting the cover loosely, sliding in the OPRV, wiggling as necessary, and only then tightening the housing cover bolts. I'm pretty sure this trick is in these-here forums; Maybe it was Clark's Garage.... ? I'm getting old and I suffer from CRS; 'Can't Remember, uh... "Stuff".'

[simssj]

Oh, and one last thing.... If you're going to all the trouble that John describes, hunting down every last hose and fitting... You may as well "as long as you're in there" do a citric acid flush. I've used this with good success: 000989102511 Genuine Mercedes - Citric Acid Cooling System Flush - Free Shipping

[iplagolf]

Well, it's been an interesting afternoon…So far this job is fighting me all the way. First I couldn't get the oil filter off. As you can see in the picture I drilled a hole in the removal tool and drove a screw into the filter to stop it from slipping. The picture of my finger is what happens when the tool slips and the headlight mechanism bites you. I'm taking the headers off. You can see the stud nuts are off. Easiest thing I've done so far. The flange bolts/nuts where the header to exhaust pipe is a different story. I may have to get the rear of the car on jack stands to have more work room. One nut is stripped (rounded) and will have to be cut off. The power steering pump was a pain trying to break things loose. I had my set of thin wrenches a couple of days ago and now I can't find them. I set them out cause I knew I'd need them. The picture of the oil in the coolant is just what was in the radiator. Oh well…I'm tired and bleeding and will fight the good fight tomorrow! Fritz

[John_AZ]

Basic early OPRV P 218 alignment tool measurements:



Repeating what simssj mentioned, if you have a socket wrench or tool with a blunt end, some use it to center the early OPRV. Finger tighten the cover bolts and wiggle the end to center as best as possible.



GL
J_AZ

[John_AZ]

OUCH!

Get a Mahle or Porsche OEM oil filter.
Purolator filters are NO good. They do not have the proper oil anti drain valve inside the filter.

J_AZ

[iplagolf]

John…Thanks for the tool info. I have a Mahle filter for the new oil. I was wondering, instead of trying to disconnect the header from the exhaust how about taking the hangers off the pipe and just dropping the whole thing to the ground. Will the header clear everything to drop out the bottom? Thanks Fritz

[John_AZ]

Check the header side clearance to the wheel well-no go. Under the engine is the BIG cross member.

Removing the header requires 4 exhaust manifold gaskets, new exhaust manifold nuts-copper is the upgrade, and exhaust manifold flange gaskets or donuts.

If you bled taking out the oil filter, you will need a blood transfer removing the header if the nuts are frozen or you snap an exhaust stud.

I do not remove the header but some do. I just wiggle the OPRV housing out ---memorizing every turn and wiggle. I used to write down/draw the housing removal path in the beginning.
OR you will swear it cannot get back on the block.

J_AZ

[iplagolf]

My thoughts are, if I get my wife at the tail pipe, with the whole exhaust system un-bolted, we should be able to get the headers off the studs and drop the whole thing to the ground, giving me free access to the cooler. Pull the tail pipe to the driver side and twist to the right to free the headers from the studs. Hell if it doesn't work, go to plan B. I don't have a plan B. LOL!!!! We'll see what happens. Thanks all…Fritz

[Slam]

I agree with John. No need to drop the exhaust. Drop the PS pump but don't disconnect the lines. Use a swivel head ratchet to get the cooler housing bolts. There are, after all, only 4. The top forward one is best got to with the oil filter off, and the water pump to hard pipe hose removed.