Leaking Master Cylinder

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John L
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Location: Covington, Louisiana

Leaking Master Cylinder

Post by John L » Sun Oct 09, 2011 9:40 pm

Guys

I have a slow leak of brake fluid where the reservoir meets the master cylinder. It drops fluid on my foot while working the clutch. Can the repair be as simple as replacing the gasket between the two? It appears that the leak is at the joint between the two.

Thanks for the help,

John

Pinzgauer Pete
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Re: Leaking Master Cylinder

Post by Pinzgauer Pete » Sun Oct 09, 2011 11:02 pm

Wipe everything clean with a rag..then have someone mash down the pedal while you observe with a flashlight chances are its either from the resovoir gasket or a a rubber seal..both are no big deal to replace..
life is like a box of chocolates...you never know which one you might get

710M

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John L
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Re: Leaking Master Cylinder

Post by John L » Mon Oct 10, 2011 9:11 pm

So I did some checking and research. If I'm looking st the diagrams correctly the leak is where the master cylinder meets the power brake booster. The master cylinder is under the fluid reservoir and where that part meets the power brake booster fluid leaks when the brakes are applied. What do I need to get to fix this? I've looked at a couple of websites and can't seem to find a gasket or rubber seal that goes into the joint. Any help you can provide would be great.

Thanks

John

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edzz
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Re: Leaking Master Cylinder

Post by edzz » Mon Oct 10, 2011 10:19 pm

Rebuild the master cylinder get the kit from Scott at E.I. or send the master cylinder to Jim for a rebuild. You don’t want it leaking into the booster.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

Pinzgauer Pete
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Re: Leaking Master Cylinder

Post by Pinzgauer Pete » Tue Oct 11, 2011 12:24 am

Yup Ed is right you will need to either rebuild or replace the master...its not too complicated ..get the rebuild kit first then remove brake lines and master, there is a clip at the end of the master that bolted to the booster that must be removed and a plunger will come out of the bore of the master that has a couple of rubber cups and seals which must be replaced. Clean out the bore with some pressurized cleaner so you can examine the bore for rust or excessive wear. You can gently clean the bore with some scotchbrite pads and once done clean out bore again with the pressurized cleaner to remove all traces of dirt, rust, or scotchbrite particles and replace the rubber parts on the plunger. You can use brake fluid to lubricate the rubber pieces it will make it easier to install on the plunger...once it is all togeather lube the bore with brake fluid and gently push the spring and plunger back into the bore making sure all the rubber cups are facing in the exact position they came out. You must reinstall the clip that secures the plunger in the bore, make sure no escaped brake fluid that wept out of you leaking master is sitting in your booster, merely wipe it out with a rag. You can at this point bench bleed the master then reinstall on the booster, reattach your brake lines and bleed out the lines. Its a good time to purge out all the old brake fluid in all the brake lines now since you have to bleed them anyway. Its not a really difficult job and your brakes should be free of leaks after you finish :D
life is like a box of chocolates...you never know which one you might get

710M

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John L
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Re: Leaking Master Cylinder

Post by John L » Tue Oct 11, 2011 7:12 am

Thanks guys. I'll check EI. I think Scott has what I need. I've never worked on a master cylinder before, so this will be a good experience. If I run into any snags I may drop you guys a note. :D

John

Pinzgauer Pete
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Re: Leaking Master Cylinder

Post by Pinzgauer Pete » Tue Oct 11, 2011 9:43 am

or you could do this and enjoy the afternoon pinzing! http://cgi.ebay.com/ebaymotors/STEYR-PI ... 4cfa96786d bolt it in and bleed lines...cheers! :D
life is like a box of chocolates...you never know which one you might get

710M

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John L
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Re: Leaking Master Cylinder

Post by John L » Tue Oct 11, 2011 10:32 am

Pete:

I like the way you think. I was looking at buying a new one and Scott has them for about $158. Have you bought from this person before? Ebay is generally good, but you sometimes run into someone not quite on the "up an up". Do you know whether this one comes with the rubber grommets to mount the reservoir? The pic seems to show them.

Also, if I do the replacement, I would remove the reservoir, unbolt the lines and then remove the two nuts attaching it to the booster. Then it should be a simple reinstall of the new unit and reatachment of the lines and reservoir.?? Aside from putting fluid back in it, what would I be missing?

Thanks, and how do you find this stuff??? :D

John

Pinzgauer Pete
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Re: Leaking Master Cylinder

Post by Pinzgauer Pete » Tue Oct 11, 2011 10:58 am

Nope you have the process right...be very careful prying out the reservoir as it is plastic and if original could be brittle spray some lube under it and around the rubber seals holding it in let it soak into the seals for a few minutes before attempting removal. As to the question of using this guy before No I have not and like to use Scott at E.I. because he is a member of our site a contributor and an advertizer so in essence he supports us not only with quality parts and supplies but in information and tips and helps keep this site going. But if you are in a pinch and can afford 100 as opposed to 150 then sometimes you have to take a chance. Me personally ...I would buy the rebuild kit and do the job myself...you will learn as you go and become very efficient at taking on other jobs that will undoubtedly come your way. For most of us these vehicles are a hobby and a source of learning unless you use your pinz as a daily driver it may be layed up a couple of days while you wait for parts and repair it and the down time is just a inconvenience rather than a major catastrophe!
life is like a box of chocolates...you never know which one you might get

710M

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krick3tt
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Re: Leaking Master Cylinder

Post by krick3tt » Tue Oct 11, 2011 12:38 pm

John,

Really, don't cheap out on your parts. A "less expensive" part may be a problem down the road...pun intended.
Get your stuff from SAV or EI, a supporter of the forum. Scott can let you know everything you might need for the
job and many here can talk you through it. Hopefully by now you have the repair manual and parts book, if not
make that purchase as well. Just a thought and my opinion. :D

Unless of course you intend to take the vehicle to a repair shop whenever it goes wrong. Even then, the mechanic
may not know the total workings of the pinz and the repair manual might be a big help to them as well as you.

I have purchased "less expensive" parts and regretted it by not having a functioning vehicle and having to ultimately
replace them with good ones...money wasted.

Morris
Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford

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John L
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Location: Covington, Louisiana

Re: Leaking Master Cylinder

Post by John L » Tue Oct 11, 2011 1:11 pm

Morris:

Your point is well taken and I'd like to support Scott for supporting us. I'll order new master cylinder and hopefully have an uneventful replacement.

Thanks for the advice.

John

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John L
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Joined: Thu Sep 15, 2011 7:48 am
Location: Covington, Louisiana

Re: Leaking Master Cylinder

Post by John L » Tue Oct 11, 2011 1:45 pm

I just ordered a replacement Master Cylinder as suggested from EI. Hopefully Scott can get it to me fairly soon and I can try my hand at the replacement.

Thanks for the help and I'll report back with the results.

John

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