Mercedes-Benz Forum banner
1 - 20 of 23 Posts

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #1 ·
I see that the MBZ water pump is discontinued can i get a recommendation for the best pump?
Thanks
 

·
CH4S Admin , Outstanding Contributor
1985 500SEC, 1991 190E 2.6.
Joined
·
45,384 Posts
I see that the MBZ water pump is discontinued can i get a recommendation for the best pump?
Thanks
I had good experiences with Graf, like OE they have a stainless steel impeller (no rust, cheapo's may be plastic) Use the 'search community' bar on top to check through W126's forum archive for 'water pump,' engine coolant system' etc
If the old pump still works a bit, this might be the best time for a de-oiling (liquid dis washer solution) flush, followed by a citric acid flush, to get rid of calcium etc deposits in the system and radiator.
I went through the whole process 'before' installing new water pump, thermostat, and all hoses with quality hose clamps.

A remote IR thermometer can be used to look for 'cold spots' in the radiator. If present, it might be worth it to have a radiator shop do the acid flush.
 

·
Registered
1989 W124 260E
Joined
·
3,571 Posts
I fitted SKF coolant pump after i found out that SKF make the bearings for the MB coolant pumps . Dont use Meyle parts,, i did 2 years ago and i had to repllace tensioner and pump again last month. Go to SKF web site put in reg number to find recomended pump for your car ..
 

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #5 ·
Yeah the pump works. It is leaking. If I remove it and clean off the crud ,put a new gasket mightn't be worth saving especially if it's original Mercedes?
 

·
Outstanding Contributor
1989 560SEC, 1989 560SEL, 1995 E420
Joined
·
5,315 Posts
Yeah the pump works. It is leaking. If I remove it and clean off the crud ,put a new gasket mightn't be worth saving especially if it's original Mercedes?
I would.
 

·
Outstanding Contributor
'17 GLS450, '14 GLK250 "Grandpa's Roadster" Project Car, 350SDL (Sold)
Joined
·
4,291 Posts
That's not usually why they leak. The impeller seal is more likely the problem, unless it's just the hose connection(s). There should be a "weep hole" in the bottom of nose of the pump, where the bearings are. If the leak is there, the impeller seal is shot.
 

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #9 ·
Yeah it’s hard to see exactly where it’s leaking since there’s so much junk around there. I know it’s in the water pump area
 

·
Registered
1989 300SE 240k miles
Joined
·
3,040 Posts
A leak in the water pump should result in coolant out of the bottom. The few I’ve replaced in my r129’s, I’ve noticed large puddles under my car(s) for a day or two. And then I found my coolant light on because so much drained out.
 

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #14 ·
My driveway is inclined. This was when I did the radiator test to 14.5psi
 

·
Registered
1989 300SE 240k miles
Joined
·
3,040 Posts
I know the v-8 and the I-6 are different, but the picture in post 8, isn’t that the thermostat housing? ..I just assumed it was the thermostat. And the water pump was somewhere above it.
 

·
Moderator
1987 & 1991 C126
Joined
·
5,751 Posts
Yeah it’s hard to see exactly where it’s leaking since there’s so much junk around there. I know it’s in the water pump area
That was how my pump looked when the big bypass hose was weeping.

M
 

·
Outstanding Contributor
'17 GLS450, '14 GLK250 "Grandpa's Roadster" Project Car, 350SDL (Sold)
Joined
·
4,291 Posts
This is the weep hole. If the coolant is not coming out there the the pump is not the problem.

Automotive tire Motor vehicle Automotive fuel system Bumper Automotive lighting
 

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #18 ·
Oh thank god .you guys saved me from having to buy a new pump. The bypass hose is on the way. I'll install a new hose and see if that does the trick .
 

·
Moderator
1987 & 1991 C126
Joined
·
5,751 Posts
Oh thank god .you guys saved me from having to buy a new pump. The bypass hose is on the way. I'll install a new hose and see if that does the trick .
I used the same clamps with good result.
One is a little larger than the other as it’s a stepped diameter hose, so proper placement is key to success. Don’t ask me how I know….

M
 

·
Registered
1986 W126 420 SEL
Joined
·
113 Posts
Discussion Starter · #20 ·
Update: i removed some parts to get better access to the back hose clamp. I tightened hell out of it and ran the engine.theres no more leak. It looks like an after market hose. It's looks really hard to remove and install so I'll wait until it leaks again and then I'll just slice it off and put a new one. What do you guys think? Or should I just go for it and put a new one for insurance?
Thanks
 
1 - 20 of 23 Posts
Top