97 E320 water pump replacement
07-16-2007, 05:42 PM
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97 E320
97 E320 water pump replacement
I am replacing the water pump on a 97 E320 (inline 6, 3.2L). Does anyone know where there is "how to" description with pictures? Also what is the bolt head size for the four bolts that attach the water pump to the block. It looks like a 5 or 6 mm torx.
07-20-2007, 02:14 PM
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'99 E430, '05 ML500, '15 GLK350
I had that issue with my 95 M104. The bolts were 6mm hex (allen), and tough to reach. An MB mechanic said he just uses a squiggle on it, but mine were so tight I was sure I'd round the bolt heads or something, so I ended up bringing it in. They replaced the bolts with normal six-sided ones.
07-30-2007, 12:32 PM
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The following is some of my personal observations for all who are interested in replacing a water pump on a 97 E320.
I finished replacing the water pump on my 97 E320. The four bolts that hold the water pump to the block are 6mm inverted hex bolts that have wave washers on them. Use a 6mm hex wrench with an extended length or a 6 mm socket.
The two closest to the firewall are easy enough to get out. The two fartherest from the firewall or closest to the radiator are the problem. The lower one can be accessed with regular tools only after you remove the two bolts that hold the power steering pump in place. Remove these and move the pump to the right and out of the way. Then you can access the lower bolt to remove.
The upper bolt is not accessible with a socket and you must use the hex wrench or buy the Mercedes special tool made specifically for removing water pump bolts which costs around $60. On my car the bolt was marked with a red marking that indicates that lock tite red was used by whoever put it in. This caused me to consult with a mechanic friend of mine on how to approach removing this bolt. He said to heat the bolt up with a mini torch and that would loosen the lock tite. I tried this and manged to wallow out the inside of the bolt due to material failure inside of the bolt. Now I needed to put a bolt remover nut over this bolt. Well it doesn't fit due to the close tolerance of the water pump body and the bolt. Mercedes must have thought that these bolts would never be hard to get out. I guess they didn't care either. So, I got a reciprocating saw and cut the water pump housing away to get enough access to put the bolt remover on this bolt. It came right out then. I bought a new bolt for $2.50 from the Mercedes parts counter. I didn't buy a new wave washer, but used a typical split lock washer that most American cars use.
When putting the new pump on the car, there was one thing that you need to consider that could have saved me some time if I had known. The solid metal hose that feeds thru the side of the water pump housing and goes to the heater controller is held down by a single bolt in front of the engine. The solid metal hose has a welded clip that sits underneath this bolt. I guess this keeps the hose in place and ensures it doesn't hit anything. My advice is to not remove this bolt. Just back it out enough to get the metal hose out of the water pump. In my case I removed the bolt and had a difficult time getting it back in. The threads on the housing that the bolt screws into had been previously stripped and I had to rethread the opening to accept the bolt.
To conclude this observation, my advice to you is to not attempt this replacement unless you have alot of tools, alot of patience, alot of time, and don't like the idea of paying $850 to a Mercedes dealership repair shop to replace your water pump.
I finished replacing the water pump on my 97 E320. The four bolts that hold the water pump to the block are 6mm inverted hex bolts that have wave washers on them. Use a 6mm hex wrench with an extended length or a 6 mm socket.
The two closest to the firewall are easy enough to get out. The two fartherest from the firewall or closest to the radiator are the problem. The lower one can be accessed with regular tools only after you remove the two bolts that hold the power steering pump in place. Remove these and move the pump to the right and out of the way. Then you can access the lower bolt to remove.
The upper bolt is not accessible with a socket and you must use the hex wrench or buy the Mercedes special tool made specifically for removing water pump bolts which costs around $60. On my car the bolt was marked with a red marking that indicates that lock tite red was used by whoever put it in. This caused me to consult with a mechanic friend of mine on how to approach removing this bolt. He said to heat the bolt up with a mini torch and that would loosen the lock tite. I tried this and manged to wallow out the inside of the bolt due to material failure inside of the bolt. Now I needed to put a bolt remover nut over this bolt. Well it doesn't fit due to the close tolerance of the water pump body and the bolt. Mercedes must have thought that these bolts would never be hard to get out. I guess they didn't care either. So, I got a reciprocating saw and cut the water pump housing away to get enough access to put the bolt remover on this bolt. It came right out then. I bought a new bolt for $2.50 from the Mercedes parts counter. I didn't buy a new wave washer, but used a typical split lock washer that most American cars use.
When putting the new pump on the car, there was one thing that you need to consider that could have saved me some time if I had known. The solid metal hose that feeds thru the side of the water pump housing and goes to the heater controller is held down by a single bolt in front of the engine. The solid metal hose has a welded clip that sits underneath this bolt. I guess this keeps the hose in place and ensures it doesn't hit anything. My advice is to not remove this bolt. Just back it out enough to get the metal hose out of the water pump. In my case I removed the bolt and had a difficult time getting it back in. The threads on the housing that the bolt screws into had been previously stripped and I had to rethread the opening to accept the bolt.
To conclude this observation, my advice to you is to not attempt this replacement unless you have alot of tools, alot of patience, alot of time, and don't like the idea of paying $850 to a Mercedes dealership repair shop to replace your water pump.
08-21-2007, 12:32 AM
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The following is some of my personal observations for all who are interested in replacing a water pump on a 97 E320.
I finished replacing the water pump on my 97 E320. The four bolts that hold the water pump to the block are 6mm inverted hex bolts that have wave washers on them. Use a 6mm hex wrench with an extended length or a 6 mm socket.
The two closest to the firewall are easy enough to get out. The two fartherest from the firewall or closest to the radiator are the problem. The lower one can be accessed with regular tools only after you remove the two bolts that hold the power steering pump in place. Remove these and move the pump to the right and out of the way. Then you can access the lower bolt to remove.
The upper bolt is not accessible with a socket and you must use the hex wrench or buy the Mercedes special tool made specifically for removing water pump bolts which costs around $60. On my car the bolt was marked with a red marking that indicates that lock tite red was used by whoever put it in. This caused me to consult with a mechanic friend of mine on how to approach removing this bolt. He said to heat the bolt up with a mini torch and that would loosen the lock tite. I tried this and manged to wallow out the inside of the bolt due to material failure inside of the bolt. Now I needed to put a bolt remover nut over this bolt. Well it doesn't fit due to the close tolerance of the water pump body and the bolt. Mercedes must have thought that these bolts would never be hard to get out. I guess they didn't care either. So, I got a reciprocating saw and cut the water pump housing away to get enough access to put the bolt remover on this bolt. It came right out then. I bought a new bolt for $2.50 from the Mercedes parts counter. I didn't buy a new wave washer, but used a typical split lock washer that most American cars use.
When putting the new pump on the car, there was one thing that you need to consider that could have saved me some time if I had known. The solid metal hose that feeds thru the side of the water pump housing and goes to the heater controller is held down by a single bolt in front of the engine. The solid metal hose has a welded clip that sits underneath this bolt. I guess this keeps the hose in place and ensures it doesn't hit anything. My advice is to not remove this bolt. Just back it out enough to get the metal hose out of the water pump. In my case I removed the bolt and had a difficult time getting it back in. The threads on the housing that the bolt screws into had been previously stripped and I had to rethread the opening to accept the bolt.
To conclude this observation, my advice to you is to not attempt this replacement unless you have alot of tools, alot of patience, alot of time, and don't like the idea of paying $850 to a Mercedes dealership repair shop to replace your water pump.
I finished replacing the water pump on my 97 E320. The four bolts that hold the water pump to the block are 6mm inverted hex bolts that have wave washers on them. Use a 6mm hex wrench with an extended length or a 6 mm socket.
The two closest to the firewall are easy enough to get out. The two fartherest from the firewall or closest to the radiator are the problem. The lower one can be accessed with regular tools only after you remove the two bolts that hold the power steering pump in place. Remove these and move the pump to the right and out of the way. Then you can access the lower bolt to remove.
The upper bolt is not accessible with a socket and you must use the hex wrench or buy the Mercedes special tool made specifically for removing water pump bolts which costs around $60. On my car the bolt was marked with a red marking that indicates that lock tite red was used by whoever put it in. This caused me to consult with a mechanic friend of mine on how to approach removing this bolt. He said to heat the bolt up with a mini torch and that would loosen the lock tite. I tried this and manged to wallow out the inside of the bolt due to material failure inside of the bolt. Now I needed to put a bolt remover nut over this bolt. Well it doesn't fit due to the close tolerance of the water pump body and the bolt. Mercedes must have thought that these bolts would never be hard to get out. I guess they didn't care either. So, I got a reciprocating saw and cut the water pump housing away to get enough access to put the bolt remover on this bolt. It came right out then. I bought a new bolt for $2.50 from the Mercedes parts counter. I didn't buy a new wave washer, but used a typical split lock washer that most American cars use.
When putting the new pump on the car, there was one thing that you need to consider that could have saved me some time if I had known. The solid metal hose that feeds thru the side of the water pump housing and goes to the heater controller is held down by a single bolt in front of the engine. The solid metal hose has a welded clip that sits underneath this bolt. I guess this keeps the hose in place and ensures it doesn't hit anything. My advice is to not remove this bolt. Just back it out enough to get the metal hose out of the water pump. In my case I removed the bolt and had a difficult time getting it back in. The threads on the housing that the bolt screws into had been previously stripped and I had to rethread the opening to accept the bolt.
To conclude this observation, my advice to you is to not attempt this replacement unless you have alot of tools, alot of patience, alot of time, and don't like the idea of paying $850 to a Mercedes dealership repair shop to replace your water pump.
09-17-2007, 02:52 PM
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Sorry it took so long to get back with you. I usually don't visit this site unless I am interested in a particular item. I had visited this site for a few days after I had made this post. To answer your question, they are the two bolts that holds the pump in place. They are on top of each other and are about 6 to 8 inches to the right of the power steering pump looking from above the filler cap. They are both the same size and it is a hex headed bolt with a nut on the other side.
When you take these two bolts out you can move the power steering pump to the side and out of the way. Don't move the power steering pump too far or it may stress the pump hoses and create a leak.
When you take these two bolts out you can move the power steering pump to the side and out of the way. Don't move the power steering pump too far or it may stress the pump hoses and create a leak.
02-12-2011, 10:55 AM
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'69 280SL, '95 E320 Wagon, '86 Toyota SR5 Truck, '69 Honda Trail 90,
My water pump leaks a little at the cover in back. I thought I could remove this cover and re-seal it. I removed the three screws that hold it but I can't get the cover off. I thought it used an O-ring to seal and it would come off fairly easily. It doesn't. Has anybody ever taken that cover off?
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11-27-2012, 09:15 PM
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Mercedes E320
I am struggling removing my water pump on a 97 E320
The directions above have been very useful. I was able to "pop" off the two inside hex head bolts near the fire wall. I ended up stripping out the lower bolt, the one hidden near the power steering pump. I started with a 5/16" drill, then worked my way up two more drill sizes (25/64) and the head of the bolt broke away. I used an angle drill that allowed me access (power steering pump removed from its bracket).
I am now stuck on the upper bolt, towards the front. I have not stripped the head yet. I have placed a 6mm-1/4" drive bit into this bolt, attached a 1/4 inch Sears wrench, and added a short copper tube "helper" (photographs added). I tried tonight - no dice, bolt did not loosen, nor did I turn the head out. I decided to post here instead looking to see if anyone has any suggestions. Note that I stuck a towel (rag) in the opening near the bolt. I lost one allen wrench and one other 6 mm bit down that opening and they are stuck on a support bracket below the water pump.
I am now stuck on the upper bolt, towards the front. I have not stripped the head yet. I have placed a 6mm-1/4" drive bit into this bolt, attached a 1/4 inch Sears wrench, and added a short copper tube "helper" (photographs added). I tried tonight - no dice, bolt did not loosen, nor did I turn the head out. I decided to post here instead looking to see if anyone has any suggestions. Note that I stuck a towel (rag) in the opening near the bolt. I lost one allen wrench and one other 6 mm bit down that opening and they are stuck on a support bracket below the water pump.
