Why do Mercedes W123 sunroofs and Power steering Pumps NEVER Fail?

[Carrameow]

Why do Mercedes W123 sunroofs and Power steering Pumps NEVER Fail? Even on the legendary Volvo 240's and SAAB 900's the sunroof's were a pain the alphabet. Also their, power steering pumps got you to 150 K only. There is something incredible about the W123 sunroof,and Power steering pump because I have never ever seen a post on these two parts

[Hit Man X]

My SD's PS pump leaks hardcore. SDL is fine.

The sunroofs do not open in weather 32°F or below and they typically operate slowly still despite being cleaned. I believe I need to grease them up in the spring.

[Pete Burton]

I think it's because they were really overbuilt and the slip clutch on the roof drive is set pretty low. The 900 roof will wind up quite a bit more before it stalls, where the MB unit will stall easily, so it gets a bit more maintenance keeping the slide clean. IMHO, SAAB should have left the sunroof manual like in the 99. I loved that thing.

[Tirebiter]

Originally Posted by Carrameow

Why do Mercedes W123 sunroofs and Power steering Pumps NEVER Fail? Even on the legendary Volvo 240's and SAAB 900's the sunroof's were a pain the alphabet. Also their, power steering pumps got you to 150 K only. There is something incredible about the W123 sunroof,and Power steering pump because I have never ever seen a post on these two parts

Sunroofs fail even on 123s. Broken cables, burned out motors, stripped gears, broken air deflector parts, and failed switches occur. Someone was looking for a drive gear in here recently.

Never changing your power steering pump fluid or filter will eventually take it's toll too but the number one cause of failure that I have seen is from trying to turn the engine with the power steering pump nut.

[pawoSD]

I turned my engine with the P/S nut.......it turned fairly easy (I did a steady pressure and it rotated).....over 3k ago, its been fine.....

My sunroof will open/close at any temp so long as there's not snow or ice all over it or anything. (Not that I ever open it between October/April anyways)

232k on my P/S pump and it doesn't leak a drop.....

[autozen]

Been turnin MB diesel engines over with the PS pump nut for over 20 years to adjust valves. Have done it on hundreds of cars without a problem. I'll bet someone did that once and coincidently the pump started leaking. That's how wive's tales get started.

It is not only 123 but all the MB Webasto sunroofs have been bullet proof through the years. When you consider how many thousands and thousands are in service, some are going to break but not many. I think the key is that MB has traditionally thrown more money at mfgs and said make it the best. That sort of ended when they went with Chrysler. MB is learning how to produce inferior products at a higher profit. Webasto now makes sun roofs for domestic cars. They have a huge plant in Michigan but the roofs are not the same. You can complain about having to repair your pop up slider and complain about the parts cost, but at least you can repair it. I was asked to look at a roof on a fairly new Chrysler. It is riveted together plastic. As far as I could tell you had to replace the whole unit, and it was a Webasto.

[KCM]

If you look at the power steering pumps on an older Mercedes compared to the American car of the same vintage, you will understand. The American cars use what I consider throw-away pumps while the Mercedes used a pump you would find on a heavy-duty truck, especially the old Vickers pump. They are simply heavy-duty and built to last. Plus the Mercedes pumps do have seal kits if a leak does start, but with an American pump you would just throw it away and buy new. I can't speak for other imports.

[Austin85]

Originally Posted by Tirebiter

Sunroofs fail even on 123s. Broken cables, burned out motors, stripped gears, broken air deflector parts, and failed switches occur. Someone was looking for a drive gear in here recently.

Never changing your power steering pump fluid or filter will eventually take it's toll too but the number one cause of failure that I have seen is from trying to turn the engine with the power steering pump nut.

That's me!!! I still need a drive gear, the one that goes in the transmission box.
It's about 1 3/4 " round and orange colored.

If anyone has access to a good new or used one Would love to hear from them.

Austin

[Hit Man X]

Originally Posted by KCM

If you look at the power steering pumps on an older Mercedes compared to the American car of the same vintage, you will understand. The American cars use what I consider throw-away pumps while the Mercedes used a pump you would find on a heavy-duty truck, especially the old Vickers pump. They are simply heavy-duty and built to last. Plus the Mercedes pumps do have seal kits if a leak does start, but with an American pump you would just throw it away and buy new. I can't speak for other imports.

Evidently you've never had experience with the Saginaw PS pump...

Robust
High pressure
Rebuildable
Etc

I must admit that yes the power steering pumps are noiseless and seem to operatre rather well! (for such a small unit)

The ones on my friends GM cars, our jeep, etc. have plastic parts...make noise...leak...fail...are horrible to work on...rebuilt units often fail.

The sunroof works great in both of my cars (the 240's is sorta stuck though...needs the new grease put in) and the 300SD's is just slow...also needs the grease.

Good designs though...usually if the roof/power steering systems are having issues then the whole CAR is having issues (ie...not taken care of )

Originally Posted by Austin85

That's me!!! I still need a drive gear, the one that goes in the transmission box.
It's about 1 3/4 " round and orange colored.

If anyone has access to a good new or used one Would love to hear from them.

Austin

I went to a machine shop and had them copy the old gear in brass. Cost $60.00 Can. Had no choice, none available anywhere.
John

[Ara T.]

The sunroof in my experience has been a troublesome lil item, on our SDL it never worked that well and on my 300D will blow its fuse.

[TheDon]

my sunroof is great.. just a lil slow i think i need to grease it.and i have the deflector on it but it doesnt pop up like it should it think.. plus the delfector part number starts with 124.. oook someone put the wrong one in

[JamesDean]

Originally Posted by Carrameow

Why do Mercedes W123 sunroofs and Power steering Pumps NEVER Fail? Even on the legendary Volvo 240's and SAAB 900's the sunroof's were a pain the alphabet. Also their, power steering pumps got you to 150 K only. There is something incredible about the W123 sunroof,and Power steering pump because I have never ever seen a post on these two parts

you just jinxed your w123.

GM p/s pump whine a lot. I dont like it.
my pump on my 300SD is SILENT!

Sunroof is SLUGGGGGIISSSHHHH unless the rails are warm.

[t walgamuth]

and volvos ran gm power steering pumps.

cheap light pretty durable considering.

tom w