S124 diff seals - Page 2 - PeachParts Mercedes-Benz Forum

spock505 · #16 05-09-2018, 11:22 AM

Spoke too soon, front pinion seal is leaking badly - does the yoke come off easily or special tools needed, thanks

dieselbenz1 · #17 05-09-2018, 01:18 PM

12 point 32mm scoket I used for my 92 w124 should be the same.

spock505 · #18 05-09-2018, 04:04 PM

Cheers, wouldn't have known but car went for it's MOT UK vehicle inspection) today, after 90 minutes chap calls me in as failed due to leaking fuel tank.

So it again went from nothing to a torrent, has anyone experienced a block breather before?

Going to remove it do the seals and inspect clean breather.

Car passed after cleaning and running on ramps, no leaks just copious amounts of diff oil.

Sugar Bear · #19 05-09-2018, 06:23 PM

Consider cleaning the breather before doing the seals, the breather could be the problem. Fill it on level surface, let it run out and when it stops put the plug back.

Good luck!!!

spock505 · #20 05-09-2018, 06:38 PM

..ta SB, any tips for getting at it, may be drop the prop coupling two rear bolts and lower down?

I have a feeling exhaust might be in the way.

After reading Strechs replies here, tap off the cap?

Cleaning differential vent/breather?

spock505 · #21 05-09-2018, 06:50 PM

Not sure how to link per post

Quote:

Originally Posted by compu_85

My differential was leaking slowly. After cleaning things up I saw the leak was coming from the fill plug. The culprit was the crush washer:

However, I noticed a slight sucking / slurping sound after I pulled the car up on ramps. I had just driven home from work, so the differential was warm and was now cooling. This made me suspect the vent. Sure enough, it was plugged solid.

Plugged vent on the left, working vent from my spare diff on the right. Even the non plugged vent was quite grubby. When you change the fluid I would recommend removing the vent and cleaning it.

Thanks,

-Jason

W126 Rear differential leak

spock505 · #22 05-10-2018, 09:21 AM

The enigma rattles on, managed after much fiddling to remove vent/breather with diff in situ - mine may be different to those above, but very simple construction.

Limited access through rear of sub frame, ideally need a stubby 17mm

The cap pops off to reveal a felt wad, further down there are two staggered flaps opposed to each other, other than that straight tube -

Refitted but left wad and cap off for now, here's the surprise, after both of those oil losses went to top up thinking bone dry, nope took two squirts of the bottle - around 1/4 at very most!

It must have been brimmed to the top, how that is possible with the filler halfway up the side is beyond me - Mulder one for you ..

Went for a short 15 mile drive, no leaks so far but not enough to get anything really hot.

Junkman · #23 05-10-2018, 01:31 PM

Have you cleaned it well then made observations after a short drive? It is truly amazing how far and by what paths vehicle fluid travels. Incorrect diagnoses are easy to make until you decide to clean. Brake cleaner on a rag and also spraying works. You want to eliminate all of the currently hanging drips but absolutely dry usually isn't necessary until it's fixed.

spock505 · #24 05-10-2018, 03:29 PM

Quote:

Originally Posted by Junkman

Have you cleaned it well then made observations after a short drive? It is truly amazing how far and by what paths vehicle fluid travels. Incorrect diagnoses are easy to make until you decide to clean. Brake cleaner on a rag and also spraying works. You want to eliminate all of the currently hanging drips but absolutely dry usually isn't necessary until it's fixed.

Yup, MOT tester did that yesterday to examine source, needed confirmation not fuel lines before passing.

It's hot here for blighty, 26c - EP90 feels like diesel for consistency, perhaps wrong fluid used, will check this.

spock505 · #25 05-16-2018, 04:29 PM

At the risk of making myself look like a bigger plonker, found out the cause of said leaks.

To cut a long story short, a large puddle of diesel appeared following PS fluid change, obviously no connection there but the car was in direct sunlight and hot too (see above posts).

bearing in mind the car hadn't been driven for 24 hours no reason for leak (no pressure, mechanical pump) unless of course actual tank pierced.

After jacking up the leak appears to be coming from one or other of duel connections just north of differential, checked bot - seems okay, released filler cap huge whoosh of air escaping - tank breather is blocked.

Because of the intermittent nature of problem (hot weather/direct sunlight) it made diagnosis difficult.

My theory is the pressure has built up to such a point as to spray fuel out across diff which in turn splashed it everywhere giving the impression of diff fluid, when the MOT chap cleaned it and air blasted, no leaks were apparent as pressure dropped, car was also inside out of the sun.

There is omly one vent to the outside air, a small pipe with trumpet valve attached, removed this which allowed more air to exit -

Vacuum tested tank without the valve which appears okay, also double clamped fuel pipes with fuel clips (not jubilee clips).

This is the valve:

spock505 · #26 05-18-2018, 04:59 PM

Cleaned and replaced diff vent today, also checked for leaks - from fuel pipes, all good.

Pressure must have been immense to bypass one or both of those fuel clamps, fuel cap pressure relief didn't act either..mmm not sure what to make of that.

Hrere's a related question that had me wondering, recently experienced fuel tank gauge issues running out while with 1/4 tank showing, would a strong pressure in the tank cause the float to ...errr not float?

edit, changed to pressure

spock505 · #27 06-06-2018, 06:35 AM

Still not out of the woods on this one yet, slight drip, drip coming from somewhere - hard location to pinpoint with rear sub frame in the way.

It appears to be north of the rubber to steel connection where both return and feed do to engine bay, is it possible for steel fuel pipes to fracture?

Double clamped

Pipes after rubber connection but fuel does not cover anything near mouting block.

Mounting block just visible

spock505 · #28 06-06-2018, 07:54 AM

Went out for a short run, back on ramps - can't be certain but looks to be coming from metal pipe inside rubber fixture, also top pipe is dripping onto lower so appears to be only one -

I think the top pipe is return so makes sense as under pressure as opposed to delivery, under vacuum.

I might change the pipes when dropping sub frame but for now will by pass connecting further up.

spock505 · #29 06-12-2018, 02:52 PM

This got to be one of those jobs where you think it's impossible to fix, the car will always smell of diesel leaving puddles everywhere.

Seriously difficult to detect with pipe fracture inside rubber mounting point above diff, fatigue must have set in or something as pipe itself is generally in good shape.

Let in a piece of nitrile fuel pipe (8mm ID) where it straightens out heading up one side of chassis, removed rubber connection to tank so no extra joins.

Even though I had matched fuel line to OD of tank spigot, the barb prevented pipe from going all the way home - add to this a 3/4 full tank, needless to say i still pen and ink of diesel

..anyhoo after a few days of driving nothing, dry as a bone - bonus also not having to pull diff for seal replacement.