Instructions on Water Pump Install

[jamathi]

I am about to replace a water pump on my 1992 300E 4-matic. I would appreciate procedure for pump replacement. Any special tools required before I start? I could probably benefit from a repair manual. Any idea where to find one. Many thanks, in advance, for any help you might be able to give me.

[jayhawk]

I just replaced mine on my 2.6. The engine is probably very similar. The manual shows removal of many components before the water pump comes out, however, I removed the air filter assembly, fan and belt, wp hoses and wp pulley. Drained coolant. Two of the wp bolts are pretty easy to get out. The other two are more difficult. No special tools except a very small 13mm rachet with a universal joint, two small extentions and for one of the bolts I used a universal joint between the extentions as well. It did not look very practical and it took several attempts to get the rachet fished up on to the bolt ...but it worked. I had to remove the two bolts that hold the front engine lift bracket and move it aside (while still attached to the tentioner shock) to have enough room to wiggle the wp out. You will need two new O rings - one between the pump and block and one for the metal hose inserted in the side of the pump. I did not use any sealant. I think I torqued the wp bolts to 25nm when I installed the new one.

[jamathi]

Thank you very much jayhawk. That will be a lot of help for me. Does anyone know where I can get the instructions for this procedure and any other tips would be greatly appreciated.

[1991300SEL]

Buy the CD for your vehicle. You'll then have all of the information you'll need for any service task you care to tackle.

There has been a ton of talk here about water pump change-out.
Go to SEARCH, key in "water pump" and search on TITLES only.

[jamathi]

So I started out by removing the radiator and fan blade and shroud. Next I took out all necessary bolts to pivot water pump freely. I could not remove the center bolt for the fan clutch so I left that on. I removed the bolts on the Y bracket; all except for the one on the left. I serched everywhere for a an allen tool that would work in this situation to remove the water pump bols and found nothing. Up till here everything was going fine. Then it happened, the lower left bolt slipped and messed up the allen part of it. I tried and tried diff. ideas but due to the limited amount of space nothin realy worked. So I went to Sears and picked up a bolt out kit. Thank god when I got home it WORKED. And the water pump came right off.

Now, one of the main concerns I have is that the rediator and water pump had stuff comming out of it that looked just like barf, throw up, & vomit. I am guessing that it is oil mixed with coolant. Does this mean I have to change the head gasket? If so how hard is it and am I off to a good start since by the water pump being removed? Does the intake and exhaust manifold have to come off in order to replace the head gasket. Give me anymore tips or ideas you guys might have.

I just wanted to say I appreciate the help you guys have been giving me. Than You

[Mr. BILL]

If you are going to tackle this one, you need to get the CD. Yes, it sounds like the head gasket is gone. Yes the exhaust manifold has to come off. Removing the water pump isn't necessary to remove the head.

While the head is off, I'd suggest taking it to a machine shop that specializes in rebuilding heads and at least have it checked for cracks and warpage. For around $300, you can have the head completely rebiult. IMO, a good idea.

I would not attemt this without the CD though.

Good luck!

[moparmike]

on my 380 I found out that I had to remove the distributor. I then promptly decided that it was something best left to the mechanics.

Hope your engine isnt in too bad of shape.

[jamathi]

Thanks for all the help guys. Does anyone know where I can get the CD or where I can get the instructions to replace the head gasket?

[moparmike]

they have all kinds of useful stuff. Mileage badges, CD's, acessories, and basic info, like telling me that those weird switches (taht dont work :-) on my back doors were seat recliners. Its really quite helpful.