1995 E300D: Need advise replacing the water pump - PeachParts Mercedes-Benz Forum

bhehmann · #1 08-29-2019, 10:12 AM

Good day.

Can anyone point me to a video or detailed procedure to replace the water pump on my 1995 E300D?

Thanks in advance,

Bjoern

Zulfiqar · #2 08-29-2019, 10:41 AM

Its the same as replacing it on the 603 and 602 engine. The only catch on the 606 engine is that the timing pointer that you will remove is adjustable. So before removing it rotate the engine to 0TDC mark, then unbolt the timing marker plate. If you dont do this step - you will face some issues when trying to do other work like timing the injection pump. (if and when you do that)

When installing you will have to stick the gasket on the pump as it will slip off and cause a leak, and because the 606 cylinder head is chunkier than the old single cam engines, you wont see the gasket slip until it you have packed it and filled it up.

Texasgeezer · #3 08-29-2019, 12:19 PM

When I changed my water pump about two years ago I did a few things that I thought might reduce future problems.

Punched a few alignment markers on the block to help check the timing pointer location (if ever needed).

Took my alternator to a local proven repair shop to check the bearings, regulator, etc.
I'm lucky having 'Start-rite Auto Electric Sherman TX' nearby. They've helped me with window and blower motors, starters, etc for years. You might have a similar place nearby.

Added a one-way-pulley OWP to the alternator. I credit that plus the new water pump's bearing to eliiminating any bounce at my serpentine belt shock.

Old Barn Guy · #4 09-02-2019, 01:58 PM

Quote:

Originally Posted by bhehmann

Can anyone point me to a video or detailed procedure to replace the water pump on my 1995 E300D?Bjoern

You can search for Mercedes remove/replace instructions for the 606 water pump, and other maintenance procedures, at Model 124 Maintenance Manual Index, which was recommended to me by dieselbenz1 some time ago. After you navigate to the page, you want to click on Section 20, then 20-1271HA.

I've also included a PDF of instructions from another site as well.

bhehmann · #5 09-02-2019, 02:11 PM

Thanks for your advise Zulfiqar.

Bjoern

bhehmann · #6 09-02-2019, 02:13 PM

Quote:

Originally Posted by Texasgeezer

When I changed my water pump about two years ago I did a few things that I thought might reduce future problems.

Punched a few alignment markers on the block to help check the timing pointer location (if ever needed).

Took my alternator to a local proven repair shop to check the bearings, regulator, etc.
I'm lucky having 'Start-rite Auto Electric Sherman TX' nearby. They've helped me with window and blower motors, starters, etc for years. You might have a similar place nearby.

Added a one-way-pulley OWP to the alternator. I credit that plus the new water pump's bearing to eliiminating any bounce at my serpentine belt shock.

Thank you Tex. Makes sense doing the other parts while I'm at it.

Bjoern

bhehmann · #7 09-02-2019, 02:14 PM

Quote:

Originally Posted by Old Barn Guy

You can search for Mercedes remove/replace instructions for the 606 water pump, and other maintenance procedures, at Model 124 Maintenance Manual Index, which was recommended to me by dieselbenz1 some time ago. After you navigate to the page, you want to click on Section 20, then 20-1271HA.

I've also included a PDF of instructions from another site as well.

Thank you Old Barn Guy.

The pdf will come in really handy.

Bjoern

bhehmann · #8 11-09-2019, 01:34 PM

So, further to my story, I just found some time to tackle the water-pump issue, and just to be sure it was the water-pump that was making the noise, I decided to spray some belt-dressing on the belt, and sure enough, it stops squealing.

Now, seeing as it's a brand new serpentine belt and idler pulley, what could the problem be? Is it possible to install a new belt incorrectly?

Old Barn Guy · #9 11-11-2019, 10:30 PM

bhehmann: I do not have a new pump, idler pulley or serpentine belt, but when I get the squeal that you've described, it also goes away when the belt is sprayed with belt dressing. I'm not sure why you are getting that issue with the new pulley and belt unless perhaps the belt is somehow not aligned? It doesn't sound like a water pump to me

my83300cd · #10 11-13-2019, 07:08 PM

Thanks for posting all the info.

The 95 e300d that my son dragged home cheap as the PO didn't have time to deal with a "running warm" issue is now to the point we can dive into that....
The injectors are rebuilt, the return lines are finally not leaking, the serpentine belt that shredded has been replaced, and the fuel system no longer looses prime when parked facing up hill. The broken heater hose that cracked at the fitting has been replaced with a new one (the used one I got from a member here lasted about 2 hrs of running time before the plastic fitting cracked)
We have a spanking new water pump, gasket, thermostat, gasket....and I just need to knuckle down.
All I want is a reliable station car, and compared to the 77 300d this thing is a rocket ship!

bhehmann · #11 11-30-2019, 04:21 PM

I checked the alignment of the belt and even reversed the belt just in case it was for some reason "directional" but the squeal still persists. Below is a link to the video. Can anyone identify the noise? Could a water pump squeal like that?

https://www.youtube.com/watch?v=OMTDPxJNJ4o

Murkybenz · #12 12-03-2019, 07:40 AM

The squeal sounds familiar to me, does it only do it on a cold engine until its part warm by any chance ??.
My 97 e300td did this squealing every time when started from cold and the noise would stop after about four minutes with the severity of the noise tailing off as the engine warmed up.
Water pump bearings were seizing up , on cold engine remove belt and you will feel the roughness in the bearings .
The belt is squealing on the water pump pulley as it cannot drive it.
My water pump was not leaking though , just bearings seizing up.

bhehmann · #13 12-16-2019, 06:15 PM

Thanks for your reply Murkybenz.

I removed the fan shroud and removed the fan and upon further inspeciton I noticed a that the belt wasn't centered on the tensioner pulley (see photo).

Could the pulley have been reversed when the belt and pulley were replaced? There is no spacer behind the pulley according to the manual.

Zulfiqar · #14 12-17-2019, 01:30 PM

The belt half way off that pulley means tensioner arm and pin aredamaged and need to be replaced

It will cause belt squeal too.

The tensioner is multipart,

The arm, the pin on which it rides on, the spring and the damper.

Buy the arm and pin along with its O ring, its about 250 in parts for genuine items, O ring is very important.

Remove the alternator and get an overruning pulley installed on it, it will prevent the early demise of the tensioner arm

bhehmann · #15 12-28-2019, 05:14 PM

Quote:

Originally Posted by Zulfiqar

The belt half way off that pulley means tensioner arm and pin aredamaged and need to be replaced

It will cause belt squeal too.

The tensioner is multipart,

The arm, the pin on which it rides on, the spring and the damper.

Buy the arm and pin along with its O ring, its about 250 in parts for genuine items, O ring is very important.

Remove the alternator and get an overruning pulley installed on it, it will prevent the early demise of the tensioner arm

Thanks Zulfiqar.

Regarding the tensioner arm pin, is the thread standard, ie: counter-clockwise to loosen? It's too tight to break loose with the standard length ratchet.