Clutch fluid disappearing

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Banshee35
United States of America
Posts: 12
Joined: Fri Sep 28, 2018 1:54 am

Clutch fluid disappearing

Post by Banshee35 » Mon Dec 31, 2018 1:58 am

Forgive the ignorance of my post as I’m new to the Pinz world.

So the one day I went to take the Pinz for a spin and clutch went straight to the floor.

Reservoir was empty. Master and slave cylinder were both dry so no external leaks. I had noticed what I thought was engine oil spots under the truck and seemed to be coming from the weep hole in the bell housing.

I filled the reservoir, bled the clutch and still see no leaking. My plan was to get a rebuild kit for the master and slave and rebuild them as parts seem cheap enough and would give me peace of mind. I noticed the slave kit doesn’t have a piston in it, does it not use a piston in the slave?

Could the drip from the weap hole be brake fluid pushing past the slave into the bell housing and then coming out the weep hole? I’d like to hope so in that then at least there’s only one problem I’m dealing with :D

TIA
Garage:
1971 Pinzgauer 710M
1969 M151
2016 Alfa Romeo 4C

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rmel
United States of America
Posts: 950
Joined: Sun Sep 25, 2011 12:19 pm
Location: Woodside, CA
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Re: Clutch fluid disappearing

Post by rmel » Mon Dec 31, 2018 11:06 am

Sounds like the Slave is leaking, pretty typical that the leak will show at the
bottom of the Bell housing.

The rebuild kits come with new rubber seals, washers etc. they are complete
kits for the job.

Make sure the bore is free of corrosion -- DOT 3, 4, and 5.1 can absorb water
and corrode the bores.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

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pcolette
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Location: Southwest Wisconsin

Re: Clutch fluid disappearing

Post by pcolette » Mon Dec 31, 2018 11:41 am

I had this exact same problem with my '72 710M back in the Spring. I went to drive it and the clutch pedal went all the way down. No fluid in the reservoir and no signs of fluid anywhere except a few drops under the bellhousing weep hole. I removed the rubber plug in the bellhousing and felt around with my small finger but it was only slightly damp in there. The amount that had dripped was no where near the amount in the reservoir. The clutch master cylinder had been replaced a few years before and also the reservoir. If the master cylinder were to leak the fluid would run out the back of it into the pedal block and then down on your feet or the floorboard. I had no fluid on the floorboard or under it.

I refilled the fluid (DOT 3), bled the system and drove away without a problem. I continued to keep a close eye on the fluid level and for the next 6 months it never went down.

I still have no real answer to what happened. In your case I think that rebuilding the clutch slave would be your best bet.

Good luck!
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
2002 MB G500 (For Sale)

Banshee35
United States of America
Posts: 12
Joined: Fri Sep 28, 2018 1:54 am

Re: Clutch fluid disappearing

Post by Banshee35 » Mon Dec 31, 2018 1:52 pm

Thanks for the replies!

I have a friend who used to restore military vehicles for a living and he came down to look at it and help me bleed the clutch.

He was baffled as well without a visible leak anywhere and thought maybe there was a chunk of something that got pushed past the seal and caused an internal leak that has now resolved after it was pushed through.

I’m keeping an eye on it but as cheap as the the slave rebuild kit is I think I will do it to be safe and see what’s going on in there. I’ve driven it a little and fluid level seems unchanged.

He said “I don’t like it when vehicles fix themselves as it just means it’s waiting for you to be far from home in the dark and the rain to declare itself.”
Garage:
1971 Pinzgauer 710M
1969 M151
2016 Alfa Romeo 4C

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rmel
United States of America
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Location: Woodside, CA
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Re: Clutch fluid disappearing

Post by rmel » Mon Dec 31, 2018 2:05 pm

I had a similar situation. This started out with a bad Master which was leaking.
I pulled and rebuilt that and flushed the system. I did notice two things. First
the seals out of the Master were badly deteriorated, and the flushed fluid was
not clear. I chalked that up to the debris from the deteriorated seal. All was
good for about a month, when all of a sudden Pedal went to the floor boards.
No leaks of the Slave so I thought it had to be just more crud that worked it's
way to the Slave seal, so I flushed again (and again) and presto started to work
fine. Been good for over a year.

It is very possible your Master's seals are starting to wear and debris is getting
into the system. I agree with your buddy, I hate it when something mysteriously
heals -- you may want to rebuild your Master and Slave, your getting a symptom.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

Banshee35
United States of America
Posts: 12
Joined: Fri Sep 28, 2018 1:54 am

Re: Clutch fluid disappearing

Post by Banshee35 » Mon Dec 31, 2018 7:37 pm

Yeah, I figure if I'm tearing down the system anyway and bleeding it I may as well do the master and slave and hopefully not have to worry about it for a while.

Total parts cost will only be about $60 and not much work.

I did find great thing to fill the reservoir though. I was looking for a funnel that I could put some tubing on to make filling it easier. I was in Walmart and in the boating section they had a pump for filling lowers on outboard motors with oil. It screws right into the bottle of brake fluid, has a pump and has a piece of tubing.

Cost me $5, remove the seal on the bottle, stick the pump in, remove the cap to the reservoir, put the tube in and pump away. Probably the best $5 I've ever spent :D
Garage:
1971 Pinzgauer 710M
1969 M151
2016 Alfa Romeo 4C

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Hotzenplotz
Austria
Posts: 300
Joined: Wed Jan 18, 2012 9:07 am
Location: Vienna, Austria

Re: Clutch fluid disappearing

Post by Hotzenplotz » Thu Jan 03, 2019 1:56 am

at this point you might as well inspect the rubber hose linking the slave cylinder to the metal tubing.
Mine was seriously brittle.
by the way, a 250 ml syringe is the cheapest tool to fill the reservoir...
Cheers
Albert
========================
My Pinz has NEVER been with any army

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