Master brake cylinder disassembly

Issues with shocks/springs, tires, stopping, etc.
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Haf-e
United States of America
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Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Master brake cylinder disassembly

Post by Haf-e » Mon May 29, 2017 10:32 am

I decided to pull master cylinder and disassemble /clean it.

I took off the circle clip on the end - and i pulled the stop screw on the bottom - but I can't get the cylinders to come out... the shaft pushes in fine and seems to hit a "stop" when released...

What am I missing?
Haf-e

1971 Pinzgauer 710M

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Disc Brake Conversion Kits for 710 and 712 Pinzgauers
www.klugewerks.com

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rmel
United States of America
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Location: Woodside, CA
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Re: Master brake cylinder disassembly

Post by rmel » Mon May 29, 2017 11:22 am

I disassembled mine this winter, it did take some effort to pull the assembly part.
I was not shy at aggressively pulling since I decided to replace it with new. It was
more of a curiosity why the front Master failed which turned out to be due to a deteriorated
gasket. Before I took it apart I did notice tool marks on the shaft indicating this had been
apart once before, my guess would be in ~2000 when she was completely overhauled.
Made me think twice about where to source rebuild parts from, this should have last
30 years not 15 :?

IMHO get a new one, esp. since they are readily available, rebuild this one as a backup,
for that day they ain't all that available. Get your rebuild kit from EI if you want 100%
assurance it's OEM. My $0.02 :)
Puller: 710K 2.7L EFI
Follower: Sankey MK 3, 3/4 Tonne
Driver: Ron // KO0Q

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Haf-e
United States of America
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Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Re: Master brake cylinder disassembly

Post by Haf-e » Mon May 29, 2017 11:38 am

Thanks - My plan is to replace it - mostly just wanted to see the condition and if it was rebuildable as a spare.

I'll go at it with some tool on the shaft. I suspect there is corrosion inside anyways. there is a sticker on the booster saying it was replaced in 1993 - which is when I think my pinz was rebuilt by the swiss.

I'll be ordering a new one from EI for sure tomorrow.
Haf-e

1971 Pinzgauer 710M

Image
Disc Brake Conversion Kits for 710 and 712 Pinzgauers
www.klugewerks.com

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Hotzenplotz
Austria
Posts: 272
Joined: Wed Jan 18, 2012 9:07 am
Location: Vienna, Austria

Re: Master brake cylinder disassembly

Post by Hotzenplotz » Mon May 29, 2017 3:30 pm

oem part info

the master cylinder is the same as the mercedes /8 series and can be rebuilt with the ATE kit RK2371
Cheers
Albert
========================
My Pinz has NEVER been with any army

one2many
Australia
Posts: 128
Joined: Sun Dec 22, 2013 5:53 pm
Location: Melbourne Australia

Re: Master brake cylinder disassembly

Post by one2many » Tue May 30, 2017 1:08 am

Compressed air should push the piston out
1985 pinzgauer 712K factory 2.7lt civilian (RHD, 4 door K)
1979 Volvo tgb 1314a (under construction to om606 diesel/722.6 trans. Dual cab/tray)

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Haf-e
United States of America
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Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Re: Master brake cylinder disassembly

Post by Haf-e » Tue May 30, 2017 3:50 pm

I got the master brake cylinder apart finally - and I found the internal stop bolt (#9 in the drawing) was loose inside of the cylinder bore - which then caused the shuttle piston (#15) to stay in a part way depressed position since the spindle piston compression spring (#8) was not properly restrained by the bolt and was instead pressing against the shuttle piston all the time, keeping it from moving properly.

This explains why I was getting weak braking and was not able to get any flow out of the front brake chamber when I tried to bench bleed it.
Master Cylinder Manual.jpg
Master Cylinder Manual.jpg (339.24 KiB) Viewed 636 times
Master Cylinder Problem.jpg
Master Cylinder Problem.jpg (610.58 KiB) Viewed 636 times
I examined all of the seals and the bore and they all look to be in good condition so I am going to reassemble it (correctly) and will give it a try.
Haf-e

1971 Pinzgauer 710M

Image
Disc Brake Conversion Kits for 710 and 712 Pinzgauers
www.klugewerks.com

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