300E water pump replacement - PeachParts Mercedes-Benz Forum

#1 07-17-2002, 07:31 PM

Hello,

Sorry for the re-post, but I searched the forum and couldn't find the steps on replacing the waterpump on the 1992 300E. I know it's a difficult job, but I have the time. Can someone tell me the procedure on how to do it , or any advice would be great.

Thanks,
Sonny

SRI inc · #2 07-18-2002, 12:45 AM

Fresh on my mind cause i did it this past weekend
And i didnt have time to grab the flx tool from snap on

Remove the shroud , pull the clip that attaches the round part of the shroud turn to the left push it over the fan remove the 2 clips holding the main shroud on the right and left they pull up, remove the upper hose, then spin the fan gently as you pull the shroud up and out then remove the round part of the shroud , remove the bottom hose on the left bottom of radiator and drain , remove all other hoses attached to the water pump including the metal pipe which slides to the left, held to the housing by a 10mm bolt and also a 5mm allen which bolts to the block under the plastic cover in the front of the cam cover, holding the belt tight around the pullys just crack but do not loosen the 13mm bolts holding the waterpump pulley and powersteering pulley, then loosen the 10mm allen holding the tensioner then counter clockwise the 13mm adjuster nut behind the p/s pump , the belt should loosen remove the belt , then loosen and remove the p/s and w/p pulleys , remove the y shaped bracket 3 bolts 2 to the p/s pump 1 to the block(13mm i believe) , then fully remove the 10mm allen holding the tensioner , then loosen the 13mm bold and 9mm bolts holding the tensioner shock remove the unit, the tensioner should come out,remove 13mm bolt that passes through the p/s pump with bolt on back and one more bolted from the back of the accesory bracket pump should now move to the side ,4 6mm allen bolts holding pump, give the socket a tap on each to get it seated deep in the allen and crack each one then remove both bottom then both top holding the pump, hold onto it as you remove both top and pull it out , swap all sensors(make sure ya dont forget the washers under them) use no sealant on any of the sensors swap the tstat neck put in a NEW thermostat in the new pump (use a behr and clock it with the purge hole in the highest position) ,clean the block surface and clean the new pump surface put a light grease (i used halamar) coating on the indent on the new pump where the oring goes,insert the oring on the pump let it set a bit (have a beer)and rebolt everything back together about a 6 hour job for me with a dive in the pool after i got everything off and cleaned up

some notes
Make sure you get the 6mm allen socket seated well , i stripped one(bottom right) and really got lucky getting it out , and those allens are a pain to find in a parts store (get a Wobble 3/8s extension set from sears)

careful of the elbow on the top of the radiator which connects the small hose to the expansion tank i must of leaned on mine a few times although not broken i am seeing it leak a bit now so i had to order a new one from fastlane today

Good time to replace your tensioner if needed and definately make the 26 buck investment on at least a new tensioner shock if ya need it or not

refill with a decent anti freeze (get you mixture right), i used the pink dex cool from what i read on the board , make sure ya burp it to get the air out check your hoses

dont know if this is the correct way and i know there are shortcuts but this worked for me , send me a email if you want and i will forward the instructions from the manual that chowpit sent me (thanks again cp)

if i left anything out please whoever reads this correct me i wrote this from memory and its fading fast in my old age LOL

jv

#3 07-18-2002, 06:28 AM

Jv,

Thanks for taking the time on giving me the detailed step by step instructions. Be back to let you know how it went.

Sonny

SRI inc · #4 07-18-2002, 10:36 AM

no prob here is another r+r thread i had bookmarked on the removal process hope it goes well

click here
94 E320 Water Pump replace method

Texholdem · #5 02-22-2010, 12:24 AM

Quote:

Originally Posted by SRI inc

Fresh on my mind cause i did it this past weekend
And i didnt have time to grab the flx tool from snap on

Remove the shroud , pull the clip that attaches the round part of the shroud turn to the left push it over the fan remove the 2 clips holding the main shroud on the right and left they pull up, remove the upper hose, then spin the fan gently as you pull the shroud up and out then remove the round part of the shroud , remove the bottom hose on the left bottom of radiator and drain , remove all other hoses attached to the water pump including the metal pipe which slides to the left, held to the housing by a 10mm bolt and also a 5mm allen which bolts to the block under the plastic cover in the front of the cam cover, holding the belt tight around the pullys just crack but do not loosen the 13mm bolts holding the waterpump pulley and powersteering pulley, then loosen the 10mm allen holding the tensioner then counter clockwise the 13mm adjuster nut behind the p/s pump , the belt should loosen remove the belt , then loosen and remove the p/s and w/p pulleys , remove the y shaped bracket 3 bolts 2 to the p/s pump 1 to the block(13mm i believe) , then fully remove the 10mm allen holding the tensioner , then loosen the 13mm bold and 9mm bolts holding the tensioner shock remove the unit, the tensioner should come out,remove 13mm bolt that passes through the p/s pump with bolt on back and one more bolted from the back of the accesory bracket pump should now move to the side ,4 6mm allen bolts holding pump, give the socket a tap on each to get it seated deep in the allen and crack each one then remove both bottom then both top holding the pump, hold onto it as you remove both top and pull it out , swap all sensors(make sure ya dont forget the washers under them) use no sealant on any of the sensors swap the tstat neck put in a NEW thermostat in the new pump (use a behr and clock it with the purge hole in the highest position) ,clean the block surface and clean the new pump surface put a light grease (i used halamar) coating on the indent on the new pump where the oring goes,insert the oring on the pump let it set a bit (have a beer)and rebolt everything back together about a 6 hour job for me with a dive in the pool after i got everything off and cleaned up

some notes
Make sure you get the 6mm allen socket seated well , i stripped one(bottom right) and really got lucky getting it out , and those allens are a pain to find in a parts store (get a Wobble 3/8s extension set from sears)

careful of the elbow on the top of the radiator which connects the small hose to the expansion tank i must of leaned on mine a few times although not broken i am seeing it leak a bit now so i had to order a new one from fastlane today

Good time to replace your tensioner if needed and definately make the 26 buck investment on at least a new tensioner shock if ya need it or not

refill with a decent anti freeze (get you mixture right), i used the pink dex cool from what i read on the board , make sure ya burp it to get the air out check your hoses

dont know if this is the correct way and i know there are shortcuts but this worked for me , send me a email if you want and i will forward the instructions from the manual that chowpit sent me (thanks again cp)

if i left anything out please whoever reads this correct me i wrote this from memory and its fading fast in my old age LOL

jv

If a water pump is leaking, doesn't it leak at the gasket? Is a replacement of the gasket not good enough? I got a w/p replace a year ago for my 1996 E320 and saw that the pump itself is a massive block, where else can it leak?

d.delano · #6 02-22-2010, 08:44 AM

Quote:

Originally Posted by Texholdem

where else can it leak?

out the weep hole, which means the bearing supporting the impeller shaft is worn out

Cal Learner · #7 02-22-2010, 11:42 AM

Quote:

Originally Posted by d.delano

out the weep hole, which means the bearing supporting the impeller shaft is worn out

Right. Rexdog, along with the other suggestions you've already been given, look up a rather detailed description of the process, together with photos, posted by Ivanerrol some time ago. Do a search on his name. He always seems to offer useful, helpful advice.