My water pump on my 92 400se has begun to leak from the “seep hole.” Since this my 1st attempt at replacing a water pump on a M119 engine, I was hoping others in the forum might have tips before I begin my venture.

I did a forum search and can't find information on water pump on a M119.

Below is the procedure outlined on the Alldata.com website for my model of car.

I have decided not to use any sealants on the “paper gasket” that accompany the water pump.

I looked into the engine bay tonight and the water pump looks fairly easy to access on the W140 body. But after reviewing the “Preparation” steps below .. Geeze.. do I need to remove the -Viscous fan clutch carrier removed and Harmonic balancer and drive belt removed. Before removing the water pump?

I sure hope not!

AllData Procedure
Preparation
• Viscous fan clutch carrier removed. See: Fan Clutch\Service and Repair
• Harmonic balancer and drive belt removed. See: Engine
Removal and Installation
• Detach coolant hoses (4), (5) and (6), attach.
• Unbolt connection cover at top (2) with engine lifting eye (1), bolt on Tighten to: 21 Nm.
• Replace gasket (2a).
• Model 210 With Secondary Air Injection: unbolt retaining plate with switchover valve for secondary air injection at coolant pump (3), bolt on.
• Unbolt coolant pump (3).
• Clean sealing surfaces.
• Replace gasket (3a).
• Install coolant pump (3) on, bolt on. Tighten to: 21 Nm.
Pay attention to different bolt lengths, see bolt diagram illustration above.
• Check cooling system for leaks. See: Testing and Inspection
• Tighten the bolts of cover at top to coolant pump to: 21 Nm

Attached Thumbnails

 

__________________
Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

i hoope not too. dont know though. seems ridiculous to have to remove harmonic balancer to do wp. if true would slow me down for the v8 cars.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Does a M119 even have a harmonic balancer? I thought (could be wrong) that only the M113/112 motors had these.

Have you checked out the Mercedes repair CD yet?

First: Place a large drain pan under the front side of the engine. A bus pan commonly used in restaurants is a good tool to have in the garage especially when performing cooling system repairs.

I think you will find that your biggest challenge will be dealing with the brackets on the left side of the water pump. The brackets secure the Air Injection pump and the Alternator. Loosen all the bolts which secure the two brackets to the front of the engine, the assembly will have a very noticeable wiggle when you have loosened all the bolts. This will provide some flexibilty so you can ease the water pump out from behind the bracket.

You will find that the vibration dampener has two notches. The larger of the two notches will provide sufficient access to the lower water pump bolts. Just rotate the crankshaft (clock wise) to align the notch with the lower left side bolt (remove bolt). Rotate the crankshaft to align the notch with the lower right side bolt (remove bolt). Remove all but the two top bolts on the water pump. Loosen the two top bolts about 4 turns and allow the coolant to drain out of the engine. After the engine has drained remove the two remaining bolts and extract the old pump. Clean the mounting surface on the new pump with brake cleaner or alcohol, this will remove the oily substance and will provide a nice dry surface for mounting the gasket. Place the gasket against the pump assembly as if it were being mounted on the engine, this helps identify which side of the gasket you will be applying adhesive to. (I prefer to use a spray adhesive) Apply adhesive to the water pump gasket then place the gasket on the pump. You’ll want to ensure the gasket does not shift or move during installation so allow the adhesive to cure before installing the new pump.

When introducing the new pump to the mounting area you will need to muscle with the alternator bracket assembly. You will want to avoid tearing the pump gasket as you slip it in between the bracket and the timing cover. Reassemble the front of the engine in the reveres order of disassembly.

PS: You may need to replace the drain tube and bucket unit as it will more than likely break during disassembly.

MrCjames...!! Thanks for the good news! As you can imagine, I wasn't very excited about removing the “Harmonic Balancer – CrankShaft Pully.” I’ve had practice removing the poly v belt tensioner, and fan clutch, so I’m “slightly” more confident about the replacement of the water pump.

Is there a particular type of spray adhesive you would recommend?

__________________
Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

Please keep in mind that if you need to remove the balancer it will not be that bad. Set the crank to the zero position then mark the belt pulley equal to the zero position on the dampener. Remove the six bolts which secure the pulley and dampener to the hub. FYI-the dampener can be snaked out without removing any other accessories mounted on the front of the engine.

If you find that you need to remove the dampener it would add approximately 20 to 30 minutes to the overall job.

I use either Gascacinch (brush in a can) or 3-M spray......................... both do well for me in many different applications.

MrCjames…. Thanks again for your insight into the changing a water pump on a M119 engine.

If you don’t mind, can you clarify one question I have regarding the removal of the balancer. I’m optimistic the removal of the balancer will not be necessary, but past experience with the S-Class has shown me to prepare for the worst. 

Since my tool collection doesn’t include a torque wrench with a rating of 400nm or 300ft lbs, I wanted to verify that I can remove the 6 bolts connecting the belt pulley and balancer to complete the removal from the hub. After reviewing a photo of the harmonic balancer, it looks as if I will need to remove the 27mm bolt in the center of the crank to complete the removal. I understand how to secure the crankshaft at the flywheel, but getting 300ft lbs of torque on the 27mm bolt is posing a problem.

Thanks in advance for any help!

Russell

Attached Thumbnails

 

__________________
Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

You should only need to remove the 6 bolts that secure the pulley and dampener to the hub. If you discover that the front crank seal needs to be replaced then "Yes", you will need to remove the 27mm bolt. Most over the counter torque wrenches will not go to the 400-NM mark so you may need to locate a torque multiplier. A rental yard that carries a good selection of hand tools may have one available so you might want to call around. If the rental yards are unable to help check with a local big rig repair center and see if some one would be willing to help a brother out. These professionals need to handle large nuts (the trucks ) and bolts so I am almost certain somebody may be willing to help if you need it.

I'll be available over the weekend if you need any other tips.

MrCjames...Thanks again for the information and advice! I wanted to let you know the water pump project went well. The only snag in the project was one of the 8mm x 135mm bolts which secures the water pump to the engine broke off while trying to remove it. Thankfully there was a short “stub” of the bolt left where I could use heat and vise grips to remove it. Having a 8mm at a length of 135mm seems like a bad design by MB. While performing the replacement of the water pump, I used the disassemble steps to also change the alternator voltage regulator, oil filter housing relief valve, left side engine mount, new hoses, and new poly v-belt.

I was VERY thankful the 6 bolts securing the belt pulley to the dampener allowed me to remove the parts without having the unscrew the 400nm crank shaft bolt..  Geeze, The fear of removing the crank bolt had me worried all week, but thankfully the belt pulley and damper came off without the removal of the 6 bolts.

I really appreciate you help and others here on the forum!

We have a 400e with 160,000 miles that my son drives, so I'm sure I will be visiting this project again .. but hopefully not soon!

__________________
Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

There is a water pump bolt above and slightly to the right of the harmonic balancer that it is impossible to get any kind of socket, combo wrench, flange wrench, crow foot flange, etc... tool on top of the bolt head.
The harmonic will have to come off.
If you don't have an air impact wrench for the crank bolt
then try a long breaker bar wedged against the frame. Just bump the starter once and the torque of the engine with loosen it.
Pull the plugs to the coils if you're afraid you'll might start then engine.

The harmonic balancer / vibration damper will still be in the way even if you remove the pulley with the 6 bolts.