[magic]

it's a 2 hour job I just did it. You don't need to remove the radiator at all, very acc...

it's a 2 hour job I just did it. You don't need to remove the radiator at all, very accessible.
Hmmm let me see if I remember
1. Drain Coolant
2. take of main fan, 10mm wrench, comes off real easy
3. take off belt, self explanatory
4. take off the 4 torx screws, be careful, they are tricky
5. take off the electromagnet for the fan, it's easier this way because it blocks some of the screws holding the pump
6. take off all the screws holding the pump, I think there is only 2 different kinds if memory serves right
7. Unplug all the electronic sensors, this can be done at any stage really, I just forgot to plug it in earlier [8D]
8. Pull off the hoses, careful coolant flowing out of them, don't flood your alternator
9. pull off the pump, take out the temp sensor and plug it into the new pump
10. Clean off the old gasket, and prep the new one with silicone on the new pump
11. make sure everything is superb, it's your car right?
12. put on the new pump and put the car back together
13. refill with coolant, leave the fill cap off, remember to replace the drain plug back.
14. Start the car, put vent fan on lowest setting, turn heat to max and wait for fan to come on
15. Add collant as the system is purged of air
16. you're done

Hope I didn't miss anything

 

[croger]

Re: it's a 2 hour job I just did it. You don't need to remove the radiator at all, very acc

Thanks for the details! ...and the time estimate. The dealer says 7 hours (at least that is what he would charge me for). Unfortunately, on the '92 2.6 the radiator needs to come off so the belt can come off and you can get to the pulleys... not that big of a job, though, since it has to be drained and disconnected anyway.

it's a 2 hour job I just did it. You don't need to remove the radiator at all, very accessible
...>8

 

[mbfanatic]

you forgot to remove your fan shroud thou
...

you forgot to remove your fan shroud thou

 

[magic]

Oh yea, forgot about that, the fan shoroud came off on mine, sorry [:D]...

Oh yea, forgot about that, the fan shoroud came off on mine, sorry []

 

[driver450190]

it's a 2 hour job I just did it. You don't need to remove the radiator at all, very accessible.

2hrs? You must be a master tech. Doing it on my 2.6 and it looks like it's going to be easily 10 hours. I'd like to see anyone do this job in 2hrs. I would pay you $200 to do it. Labor plus parts.

 

[sranjesuper]

the guy was describing the job on a 2.3

but OP has a 2.6

i did this a long time ago and i think it is easier to remove the rad for any work on the engine IMO, since it is quiet easy to remove. Especially if your AC doesnt have any freon, then you can just rip the whole unit out as one..

 

[twichel04]

Yeah the 2.6 is a little more tricky, but can be done in 2-3 hours depending on skill level. do your self a favor and take the 5 extra min to remove the radiator, it will save you alot of time and frustration in the end.

 

[es250nut]

I did it without removing the radiator. Of course, I had the head off along with the intake. I think, I could do just the water pump in 2 hours by itself. Maybe three or four if beer is involved.

 

[ghartin]

With the radiator off the job is easier and gives good access to other parts you might want to look at such as worn pulleys, CPS, belt tensioner, hoses, and crankshaft seal. Also a good time to have the radiator cleaned.

 

[twichel04]

With the radiator off the job is easier and gives good access to other parts you might want to look at such as worn pulleys, CPS, belt tensioner, hoses, and crankshaft seal. Also a good time to have the radiator cleaned.

Exactly, it is quite possible to replace the pump on a 2.6 with the rad in, but it makes it easier with it out, and only takes an extra 5 min to do, and it also removes the possibility of damaging the rad while you're working in there.

 

[MacktheKnife]

I did the water pump on my 3.0 for the same reason about 3 weeks ago now. Took me about 8 hours total (10pm-6am), 2 beers, and 3 cigarettes, but an hour or two of that was spent waiting out a rainstorm. I'd say I'm pretty skilled at this (I pulled the 2.6 and put the 3.0 in myself), and it still took me 6+ hours.

My process: remove bumper, drain coolant, remove fan and shroud, separate coolant radiator from AC radiator and remove coolant radiator, remove belt, remove water pump pulley, and this is where it got tricky. Using 2 flex fittings and a 6" and 3" ratchet extension, I got the top rear and bottom rear water pump bolts. Used a standard allen wrench to get the top front, but to get to the bottom front bolt, I had to unbolt the power steering pump and push it off to the side, and remove the belt tensioner. Once the PSP was out of the way, the last bolt was pretty easy to get to, and it came out easily enough from there. Follow the same process in reverse for installation, and make sure you use new O-rings and silicon sealant. I didn't remove anything other than what I listed here, and that made for some pretty tight working areas, but it's definitely doable if you're brave.

 

[GaryStofer]

Mercedes 2.6L engine water pump removal steps

You will need about 5 hours to remove the pump and 4 to 5 hours to put it back together. Here are the steps I take:

1.) Remove the temp sensors from behind the license plate ,remove tie wrap on cable that ties the sensors to the bumper.

2.) Remove the plastic cover from the RH wheel well to get access to the bolts holding the bumper.

3.) Remove bumper , 4 nuts and two bolts

4.) Remove driver side headlight assembly to provide work space. 2 bolts on top and one on the bottom in the middle of the assembly. (First remove the little painted trim piece under the headlight)

5.) With bumper removed attach hose to radiator fluid drain and empty system.

6.) Remove fan shroud

7.) Remove frame cross member on top of radiator complete with front strut. Unhook hood latch cable and put aside. 6 bolts on top and one on front strut.

8.) Remove dual electric fan assembly,4 Phillips head screws and 2 bolts and set aside.

9.) On lower left corner of AC radiator (drivers side) remove clamp holding AC coolant line to fender. (next to hose and hard line coupling.

9b.) Remove both radiator hoses and little stub hose on top and set aside.

10.) You can now pull the radiator assembly out of the bottom rubber sockets and move it slightly up and forward to give you enough space for wrenches and to remove long bolts later.

11.) With the belt still on tight loosen the bolts on the water pump and steering pump pulleys, but don't take them out all the way yet.

12.) Loosen the big bolt going through the center of the belt tensioner. 19mm socket.

13.) Loosen the tension on the belt all the way and remove the belt and the two pulleys now.

14.) The fan assembly is mounted to an Idler pulley which is mounted to the axle with 4 bolts. There is a groove on top of the housing where the pulley and the fan assembly are spinning. The pulley has a hole that lines up with the groove in the housing. Using a torx screwdriver bit that fits snugly into the groove and slides forward into the hole on the pulley you can lock the pulley so that you can loosen the big allen head bolt holding the fan assembly and then loosen and remove the 4 bolts holding the idler pulley.

15.) Remove the idler pulley. It's made out of aluminum and fits tight against the hub. Carefully wiggle it loose, trying not to bend it.

16.) Now you can remove the bolt that was behind the idler pulley and the other two long bolts holding holding the belt tensioner.

17.) Loosen the large bolt in the middle of the tensioner and remove it forward and upward.

17b.) While you have that tensioner bracket out you might want to consider modifying it so that it can be removed without having to take the fan assembly off. I cut mine at the appropriate location and tied it back together with a flat steel and some bolts.

18.) Remove the air intake for more work space.

19.) Remove steering pump and place it into the space vacated by the headlight assembly. Use a bungee to keep it out of your way.

20.) Look behind the water pump and locate two Allen head bolts that hold AC piping in place (originally painted red by Mercedes. With a suitable Allen wrench and some pipe as a handle for leverage loosen the bottom bolt a couple of turns and remove the upper bolt. Now move that AC hose about 1/4" toward the back to give you straight access to the bottom rear bolt of the water pump with a long 1/4" extension and a short 13mm socket. Might have to use an extension on the ratchet to break it loose.


21.) For the top bolt use long swivel extension or swivel joint with long extension.

22.) Now remove the two easy bolts on the front of the pump and knock it loose.


Notes on reassembly: The bolt on the tensioner bracket for which you had to remove the idler pulley is sitting in oil. You will need thread sealant Loctite 592 or equivalent. While you are at the store get 1 1/4 inch id radiator hose for the little stub section. Don't assemble new pump with old hose or you kill yourself when that starts to leak 3 months down the road.

You might want to cut and join that tensioner bracket with a piece of flat iron made to fit in the U-profile and two screws. This will ease of maintenance should you have to replace the tensioner or the pump again later. Before you cut make sure that you don't create an interference with the bolt heads and nuts.

 

[plinker17722]

NUMBER 19 is important you will not be able to remove the coolant pump screws with the pas pump in place .Also check out , that the screws holding in the power steering pump are secured with bolts of different sizes And the best help you can have is a camera to take pictures as you will know how things go back, just in case. I put all the bolts i removed from pas pump back in to the pas pump as i removed them tie the pump up out of the way . And replace the small hose from pump to head .A good set of alen wrenches are your best bet to remove the pump to block bolts and clean out the bolt heads before you put the alen wrench in .I swapped my alen wrench type screws out for bolts. Doing this will make the bolts easy to removal next time . The wrench damages the top of the hexagon heads making next removal even more difficult And as others will say no dont ...i did use sealant on the coolant pump face - Hylomar blue on my pump bolts and face .If you do this and you fit the pump do not remove the pump once its in place or it will displace the o ring and you will have to remove it clean it and try again.. Good luck .We are all hear to help you.

 

[timgrishkevich]

You have a 2.6, it will be far more time consuming than on a 2.3.

Just follow the instructions exactly on this article:
https://www.pelicanparts.com/techar...er_Pump/24-WATER-Removing_Your_Water_Pump.htm

I did the job a few months ago. Took me a full day with basic tools. Not difficult at all, just keep all your bolts and parts organized.
Yes you will have to remove the radiator. Bumper/radiator removal takes 45 minutes and it makes the job far easier. It also does not hurt to flush the coolant before putting in a new water pump. This way, radiator removal is not a waste of time. Take an air gun and carefully blow on the radiator to remove 30 years worth of dust/debris. You should have seen how much garbage came flying out of mine. Replace all hard/cracking hoses as you go along.

Here is a link to my thread on the same issue a few months ago:
https://www.benzworld.org/forums/w201-190-class/3010026-leaking-water-pump.html

There is a weep hole in the waterpump that begins to leak when they are failing. At the bottom as you mentioned. Replace it before it fails completely and you blow a head gasket.

A link on how to do a proper coolant flush just to be thorough since you're taking everything apart anyway:
https://www.pelicanparts.com/techar...ATER-Coolant_Flush/23-WATER-Coolant_Flush.htm

 

[plinker17722]

extra job

One more item i have thought about . The lifting eye on the rear of the engine do replace the o ring in there at the same time you change the coolant pump .I had a coolant leak just after i did the job and thinking the worst that the head gasket had gone .But it was this o ring . The heater hose is fitted to it also .See picture .

 

[Teutone]

+ 1 That little O-ring is a must, but isn't there an identical o-ring on the other side (part 0129975148?), to also have an extra thermostat O ring is a good idea too.
If you are not replacing all hoses at the same time, to replace the short 2 size hose water pump to head is essential imo.
If issues come up, this short hose you cannot replace unless you take everything apart again, all other hoses you can always get to.
I usually replace the idler wheel (they can get noisy) and the serpentine belt at the same time.
Careful with loosening / tightening the tensioner, left turn doesn't always mean loose and visa versa. Experiment first.
Use good hose clamps. Personally, I would rather use some original clamps from the wrecking yard, than a new set of cheap china clamps.

I had to replace a tensioner (the aluminum bolt's thread strips easily) and another time had to replace the shorty hose, so I learned the hard way.

The short hose is cheap, parts # 1032030082 i think.

My replacement Graf water pump is doing well for 50K + miles.

 

[plinker17722]

Also manual informs that sealant must be used on one of the bolts going in to front of engine .If its not sealed you will have oil leaking from it in the future.

 

[Teutone]

Also manual informs that sealant must be used on one of the bolts going in to front of engine .If its not sealed you will have oil leaking from it in the future.

Oops, I haven't done that last time, which bolt is it?
My manuals are on another laptop, which I have been reluctant to take apart (big hands) and re solder power plug to board.

 

[SpartanV]

Also manual informs that sealant must be used on one of the bolts going in to front of engine .If its not sealed you will have oil leaking from it in the future.

Do you mean the bolt that goes through the tensioner bracket and the bottom right side of the upper timing cover? That is oily when pulled IIRC.

Or are you talking about one of the actual water pump bolts?