92 400E Power steering pump and water pump, need advice - PeachParts Mercedes-Benz Forum

kanio · #1 09-14-2006, 05:48 PM

Hello, I am a new owner of a 92 400E with 170K. First time Mercedes owner. With its age, it will need a lot of maintenance to bring it up in good health. Currently, there is a big power steering leak and I suspect it is the hose between the reservoir and the pump. Because the pump has been run without fluid few times, I bought a rebuilt pump from ******** to replace the leaking one. I removed the 2 bolts that hold the steering pump bracket ( one under the reservoir and the other one behine the bracket on the driver side), but the bracket don't want to come off. Am I missing a bolt somewhere?

Also, as part of the maintence, i like to replace the water pump. However, I see that one of the mounting bolts is behind the big harmonic balancer. I don't see a way to loosen that bolts without taking out the cooling fan bracket (that will make me to take out the alternator) and the harmonic balancer. If I am right, is it worth it to do? Or should I wait until the water pump fail?

Beside that, here is my maintence list to bring the 400E back to life:

change out tranny fluid filter, tranny fluid, oil change, caps, rotors, wires, plugs, new power steering pump, filter, differential oil, drive belt change, new fan clutch, coolant change, thermostat change, and drive belt tensioner change.

Am i missing anything?

Gilly · #2 09-14-2006, 09:15 PM

I'd forget about replacing the pump. You can unscrew the nipple from inside the reservoir (actually the "foot" the reservoir attaches to) and then easy enough (relatively speaking) to replace the hose. Get the right hose, hopefully a dealer will sell you a small quantity of it.
water pump bolt, if I'mnot mistaken there is a notch in the harmonic balancer that allows access to the bottom bolt ot bolts.
Gilly

kanio · #3 09-14-2006, 10:03 PM

Thanks for the quick reply. I hope there is a notch on the harmonic balancer, or it will be a stupid design.

i took part of the old steering pump out already. I like to have a new pump in there, so i don't get that grinding noise if the pump was damage.
anyone will like to comment on how to take out the power steering pump bracket?

kanio · #4 09-15-2006, 12:44 AM

Bump

Gilly · #5 09-15-2006, 05:15 AM

Unless the steering gear box is also leaking, it's really unlikely the pump was low enough on fluid to be damaged, or unless the radial sealing ring is also leaking. The connecting hose leaking is a fairly common failure, the pumps are very durable. What part of the pump have you taken off, can't you just put it right back on? Sorry, I obviously don't know the answer to what you're asking about the bracket, don't recall removing one. If nothing else you can subscribe for a day to www.startekinfo.com. Also wanted to mention there was a bulletin on the hose leaking and that has a list of parts you should have. Besides the hose they wanted you to replace the nipple itself, plus there is a sealing ring under that nipple, and a gasket between the reservoir and bracket.
Gilly

kanio · #6 09-15-2006, 03:53 PM

The bracket I am talking about is item 30a in the picture. Does the pump, item 30, just come out by removing the 2 bolts, item 46, that mounts the pump to the bracket?

gsxr · #7 03-05-2009, 04:34 PM

Quote:

Originally Posted by kanio

The bracket I am talking about is item 30a in the picture. Does the pump, item 30, just come out by removing the 2 bolts, item 46, that mounts the pump to the bracket?

Never got an answer on that, huh? Anyone? Bueller? Bueller...?

I'm about to tackle the same project... and since it doesn't look like the pump can easily be removed from the bracket, I may just try to re-seal the pump by pulling the face off, as described in this post:

Power Steering Pump Reseal Question

speace · #8 03-05-2009, 06:35 PM

I recently replaced my PS Pump on my 92 400E.

Getting it off was a real pain. If I recall, there are a couple of CAP SCREWS with allen heads that have to come loose from behind the bracket. There was also a support for a wire harness that was under that same screw.

I know you don't want to hear this, but I had to unbolt my motor mounts and jack the engine up about 4 inhes to get the clearance I needed.

I had JUST finished replacing my motor mounts before starting on the the PS Pump, so I just loosened them back up and obtained JUST enough room to work...

There are two bolts per side that go vertically into stationary nuts trapped in the motor mounts. I dropped the 4 of them, put a board under the oil pan and used my floor jack to raise the engine. Going back in, it was a bit of a pain getting those 4 bolts to line back up into the mounts. You have a little movement in the motor mount you can work with if the weight of the engine is not on the mount while you are putting the bolts back in. Careful, it is easy to get the little bolts cross-threaded when trying to start them if the mount isn't perfectly above the hole.

Perhaps someone else here has a better solution? This is what I worked out...

Oh, and once it was all over, my belt tensioner gave up the ghost! All of that oil being slung around on the belt got to the rubber in the tensioner and it lost all tension. I think that little gem cost as much as the rebuilt pump!

Best of luck on this! Keep us posted!

gsxr · #9 03-05-2009, 07:46 PM

speace, just curious, was there a particular reason why you replaced the pump instead of re-sealing it? I'm about to attempt the disassembly-and-reseal on my E420 tomorrow night and Saturday. Should be a whoppin' good time.

speace · #10 03-05-2009, 07:51 PM

No, I probably could have re-sealed it. I only wanted to do it once and having a fresh pump would decrease the chance of a re-do. I found a good price for a rebuilt unit at a nearby parts house. The core charge was outrageous!

There are lots of places for leaks in the reservoir setup and connector hose. Be sure the pump itself is the problem before you go to all that trouble.

In my case, it was definitely the pump.

emerydc8 · #11 03-06-2009, 09:40 PM

Check out my post on this. Mine was a 93, but it was made in late 92. I believe the two power steering pump bracket bolts went from the back of the bracket towards the front and they were 13 mm. I didn't have to loosen the motor mounts, but it is a tight fit to snake your arm up there to reach the bolt heads. As I recall, I had to lay on my right side with my feet pointing forward to get my arm and wrist to bend so I could reach them.

400E Power Steering Pump

emerydc8 · #12 03-07-2009, 05:48 AM

Kanio:

Quote:

Also, as part of the maintence, i like to replace the water pump. However, I see that one of the mounting bolts is behind the big harmonic balancer. I don't see a way to loosen that bolts without taking out the cooling fan bracket (that will make me to take out the alternator) and the harmonic balancer. If I am right, is it worth it to do? Or should I wait until the water pump fail?

On mine, the damper had to come off to get the last bolt out of the waterpump. If you take the damper off, you will be disturbing the main crank seal. The bolt is a 27 mm bolt that I was able to loosen with a floor jack under a breaker bar. Unless you have a fancy crank lock tool that they use at the dealer, your second option to stop the crank from turning when you try to loosen and tighten the crank bolt is to take out one of the three torque converter bolts and install a long bolt with some sleeves on it to hold the flywheel from turning when you loosen it. In this link I posted a picture of the makeshift crank lock. 1989 560 Sel Water Pump Need Help

There is a special tool that MB has to install the new front crank insert and seal which makes it really easy.

gsxr · #13 03-07-2009, 10:08 AM

Quote:

Originally Posted by emerydc8

Check out my post on this. Mine was a 93, but it was made in late 92. I believe the two power steering pump bracket bolts went from the back of the bracket towards the front and they were 13 mm. I didn't have to loosen the motor mounts, but it is a tight fit to snake your arm up there to reach the bolt heads. As I recall, I had to lay on my right side with my feet pointing forward to get my arm and wrist to bend so I could reach them.

400E Power Steering Pump

emerydc8, your other post (and photos) were a HUGE help. Thanks for posting all that info! Based on your pics, I was able to remove the pump from the bracket, without removing the bracket from the engine. The two Allen-head (socket-head cap screws) which screw into the rear of the bracket take some creativity to access, but with those out, the rest was a breeze. I will take some pics of my project and post them on your other thread. I hope to have everything back together later today...

emerydc8 · #14 03-07-2009, 03:06 PM

Wow. Getting the two rear bolts out is the hardest part. Once you get those out, the bracket is only held on by one or two more bolts in front, which are easily accessible. I'm glad the prior posts helped.

gsxr · #15 03-08-2009, 01:15 PM

The job is now complete on my car, and as of now the leak seems to have stopped. I suspect the majority of my leak was from the short hose below the reservoir, but there was so much grime I couldn't tell for sure. I had already replaced the curved S-shaped hose below the pump and that didn't fix the leak. Since I had the parts in hand, I went ahead and re-sealed the pump, as well as the reservoir itself. Satish (and others) have said you can replace the hose without removing the pump from the bracket, but dang, that has got to be tough to cram the hose into the small gap between the two hose barbs! No way I would attempt that, I'd just pull the pump to change the hose.

I think the book time of approx 4 hours to R&R the pump is about right, plus another hour to re-seal the pump on the workbench. Add another few hours to scrub everything in sight since you'll probably have a ton of oil and grime from the leak.

Anyway, I found it was relatively simple to pull the pump off the bracket, and leave the bracket attached to the engine block. Removing the plastic air duct which cools the engine mount helps considerably. I also removed the side plastic panel which goes around the sway bar. It takes an extra 10 minutes but it's worth it for the improved visibility & access to the rear bolts. Once the pump is off the bracket, everything else is a breeze. The worst part of re-sealing the pump was getting that blasted circlip removed.

On a related note, I found an easy way to empty most of the fluid from the system prior to disconnecting any hoses. Siphon the reservoir empty, then insert a length of hose that is approx 1/4" OD into the return hole in the side of the reservoir. Hold it in place tightly by hand. Route the other end of the hose into a container. Have a friend turn the steering wheel back & forth, from lock to lock. The movement from the steering box will suck fluid through the system and pump fluid out the hose. When all the fluid is out, there will be very little mess when you disconnect any of the hoses in the PS system. I used the same concept to "flush" the old red fluid out, by pouring clean yellow OE fluid in while the old stuff was being routed to the container. After a quart or two goes through the system, it's probably 95% flushed. Works great, and no need to have the engine running!

Also - when re-filling the system, turn the wheel lock to lock while making sure the reservoir never goes empty. When the level no longer decreases, the system is full. Even after you start the engine and the pump is running, the level should not change.

Photos below. Hope this info helps y'all for future reference!

search keywords: 400E 500E E420 E500 M119 1992 1993 1994 1995