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Reservoir Leak

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sideshowbob
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Posts: 117
Joined: Mon Aug 01, 2011 2:18 pm
Location: Hampshire UK

Reservoir Leak

Post by sideshowbob » Sat Aug 10, 2019 6:07 pm

Have just recently been cleaning my engine bay on my '88 635Csi and have noticed on the box section below the power steering reservoir a build up of fluid.
This appears to be coming from the base of the power steering oil reservoir there are several pipes/spigots attached to this reservoir (presumably flow and return) and it would appear that it is coming from the pipe that is on the base of the reservoir.

The leak is not coming from the junction between this pipe and the attached flexible hose as this junction is somewhat remote from the resevoir and the build of leaked oil is directly under the reservoir.

A new reservoir is somewhat expensive and a second hand one while difficult to find may not be in any better condition than the one on the car.

I am wondering if I could remove my leaking reservoir and have the spigot pipes rewelded to the main body thus stopping the leak.

Has any one else experienced this failure and if so what was your remedy.

Thanks

sideshowbob
Bigcoupe supporter
Posts: 117
Joined: Mon Aug 01, 2011 2:18 pm
Location: Hampshire UK

Re: Reservoir Leak

Post by sideshowbob » Sun Aug 11, 2019 9:37 am

I might have jumped the gun on this one. Have now thoroughly cleaned all around reservoir and input / output pipes, also cross member under reservoir.

Good news is that overnight there appears to be no build up of fluid anywhere.

Looked at previous posts, which is what I should have done initially and wondered if reservoir is over full as I have just recently had the power steering pump reconditioned.

With engine cold and not run for several weeks I took the top off the reservoir and the fluid was well above the filter screen, in fact about 10 - 12mm below the rim of the reservoir.

Replaced lid and then gave the car a good run, in fact also stopped and started a few times and then finally rechecked level of fluid straight after this run. Fluid was now about 5 - 6mm below the rim.

In previous posts Ron has stated that when cold and left standing for several weeks fluid just be 3/8ths below rim, dropping to below filter when engine has been run returning to higher level when presure in brake bomb reduces.

I am experiencing movement in the levels but not to the degree that Ron suggests....could there be a problem with the brake bomb or is my reservoir just slightly overfull.

I have not noticed any problems or deteriation in the cars braking efficiency or any differences in brake pedal pressure.

Am I worrying over nothing or is something happening that I should be aware of ?

Thanks

ron
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Posts: 4407
Joined: Sat Jul 10, 2004 11:35 am
Location: South Wales U.K.

Re: Reservoir Leak

Post by ron » Sun Aug 11, 2019 10:30 am

With the engine OFF pump the brake pedal until it goes hard. Now check the level. Should be about 10mm. from the top.
They are ALWAYS rustier than you thought!!!!!!
'85 M #228
'87 M #367
'88 High line.
'80 735i

sideshowbob
Bigcoupe supporter
Posts: 117
Joined: Mon Aug 01, 2011 2:18 pm
Location: Hampshire UK

Re: Reservoir Leak

Post by sideshowbob » Sun Aug 11, 2019 12:53 pm

Hi Ron, thanks for that prior to your reply I did that and guess what , fluid leaking out of top of reservoir.

Have now concluded that garage that took power steering pump off have overfilled reservoir.

Spent last hour cleaning up excess fluid !!

They obviously are not aware of fill up and levels procedure on our cars.

I only hope the firm that rebuilt the pump are more professoinal than they were at refitting and refilling system.

During all this 'mess' I have noted that there is no rubber gasket/seal on the reservoir lid. Would you know where I can get one from ?

Noted on other posts that it is not listed as a BMW part

Thanks again.

sideshowbob
Bigcoupe supporter
Posts: 117
Joined: Mon Aug 01, 2011 2:18 pm
Location: Hampshire UK

Re: Reservoir Leak

Post by sideshowbob » Sun Aug 11, 2019 10:50 pm

Double checked levels again later today and now noted that my cover does have the rubber gasket in situ.
However it was not what I was expecting. I thought it would have been similar to an O ring but it is quite broad andvgrey in colour, which makes it look like a machined surface, hence my initial impression that it was missing !

Any way another problem solved.

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