master cylinder push rod connection

I've been doing work on the brake/clutch pivot arm (to get rid of some wobble) and in doing so the brake pedal just seemed to pull the brake master cylinder push rod out and now it dangles free, still attached to the brake pedal arm. At the end of the master cylinder is a completely deteriorated rubber boot that 90% of fell on my face while staring up at it There remains about 1/2" of boot still attached to the mc. My questions are: 1. Is the boot the only thing that holds the push rod in its correct place? If not, the end of the push rod has a washer/disk sitting right behind a "polished" knob at the end of the rod. Is this washer/disk supposed to hook-up to something because I can't tell what purpose it serves. 2. How is the rubber boot attached to the mc? Just pushed on or is there some sort of retaining clip/ring? 3. Does anyone know a source for this mc rubber boot? Closest I could find was part of a $50 rebuild kit - ouch!

I've scoured the forum and my manuals and I can't find pics or dialogue. On a couple of threads I've actually found conflicting information but I think it's because of dealing with different year Jeeps/mc's. Mine is a 71 CJ5 with a dual-reservoir mc which I believe is original.

Any help would be much appreciated.

 

That boot is mostly just a dust cover, but it seals the push rod and master cylinder so it some what hold the rod in place long enough to install the clutch petal return spring. Oozing brake fluid rots the boot.You need to replace it. there has been lots of discussions on this site about this. New is the best course of action. I think you can buy them through napa, others will chime While you have the brake system opened up this would be a good time to replace the rubber lines to the front wheels and the one on the rear axle and of course inspect all brake lines replace if needed. good brakes are your best friend. good luck.

 

Kevin,
It sounds like you have lost the retaining clip/ring that holds that washer thing into the bore of the MC.
If you have the same master cylinder that I think you do (because I have the same one on my '70) you will find these master cylinders are hard to find as well as any rebuild kits for them.
I think Walcks is selling a reproduction master cylinder to replace it, or I think the master cylinder that Herm sells can be used also.
What is different about the original Wagner Lockheed master cylinder is that it has a stepped bore. That means the bore for the back piston is larger than the bore for the front piston. If you take your master cylinder apart you can readily see what I mean. The original Wagner Lockheed master cylinders are long out of the system, as well as the rebuild kits for them.

Don

 

Here's the end of the push rod showing the disk/washer.



Here's not a very good shot of the end of the mc, where the push rod goes.



Other than the rubber boot, is there something that holds the rod against the piston assembly or is the "washer" at the end of the push rod supposed to be pushed into the mc bore? When I started to try doing this, I got brake fluid pouring out on me as soon as the piston pushed back from the end of the mc....

 

Kevin,
There is a groove just inside the end of the MC bore that holds the circular spring wire clip that you are apparently missing. The slotted washer thing goes inside the bore and the spring wire clip goes in next and seats in the groove. That's what is supposed to hold it all together. To dissasemble an original with all the parts you pry the rubber boot away from the MC, slide it up the pushrod as far as you can and remove the spring wire clip.
It sounds like the seals in your MC are shot if it dribbles a lot of fluid out the end of the bore with the pistons still in place. Sounds like you need to look for a replacement. There are a couple of places I have heard of that will rebuild your original, even to the extent of sleeving the bores with brass and fabricating new pistons if the old ones are corroded beyond use, but these are expensive (to the tune of $300-400).I think you are better off to get one of the later production dual reservoir MC as sold by Herm or Walcks. I think these are not the stepped bore, but have the same size pistons for both front and rear brakes. These should work OK, worst case is you may end up adding a proportioning valve to the rear brakes to prevent rear brake lockup on a hard stop.

Don

 

Picture=1000 words

2000 words

 

I was able to buy a Lockheed MC from NAPA but that was a few years ago. It was the same or very similar to the original from my 70. It was more $ but I think it was worth it. The clip that goes in the groove was difficult to get in. My fingers are too small and weak so I had to get a friend to pop it in there for me. Note that the above picture is for a single MC but the clip setup is about the same. Good Luck

 

Thanks guys. Here's the pic from my manual, showing the dual reservior mc arrangement. The pic is confusing because it doesn't seem that the snap ring (#2 in pic) has anything to do with the push rod, which isn't even shown. And the "cut washer" currently sitting on my pushrod doesn't show in the drawing either. From this picture it looked like the snap ring (#2) holds the end of the piston together and gives the boot something to grab hold of. If you can make out the instructions under Reassembly "f", it says "Install the pushrod assembly, which includes the push rod, boot, and rod retainer, and secure with the snap ring." I assumed the "rod retainer" was the cut washer and the snap ring was the ring that is currently holding the cut washer on the push rod. My thinking was that the boot was actually holding the cut washer in place and the push rod against the end of the piston.




Based on all that I've read in various threads on this forum it seems "rebuilding" is iffy at best and probably way beyond my skills, so I think I'll spend time looking at a new mc. Interestingly, many folks seem to have problems with new mc's showing up with push rods that are the wrong size or are not provided at all...making me think I am going to have to deal with figuring out a way to get my current push rod to go into a new mc anyway....

 

yup. All that holds your master cylinder, and both forward and aft brake systems in check is that pesky little wire clip. Clip fails, the system fails. Seems odd that while the requirement for dual systems was made to improve safety that a tiny wire clip (that is subject to rust and corrosion) could defeat the whole system.

A new master cylinder can be had for around $120 and is available at 1-800-the-jeep (Turner 4wd in Atlanta) They sell them on ebay as well under the name "twoeyesofblue". It is the m/c with dual diameters inside the m/c -- just like the original.

Don't discard your old push rod until you have the new m/c installed and functioning. In fact, don't discard the push rod at all. Someone out there needs it and they don't sell push rods by themselves. If you have an F-134 4 cylinder engine, save the old m/c, 'cause you're going to need to move one fitting from the old m/c to the new/mc. It'll be obvious which fitting needs to be moved..

good luck

Oh I forgot -- I can get you the wagner part number for a rebuild kit for your m/c if you want it. I have a kit in the shop and can pick up the part number off of it. I plugged that number into ebay a couple of years ago and there was a seller in Turkey that had lots of them. I bought three, but I only have one left that I will likely need. Send me an e-mail or just post a reply on this thread if you want me to get the number -- I'll post it in this thread. It is "something, something 046" as I recall.

In addition, the master cylinder is the same as the dual m/c that was used in International Scouts. That probably won't help much since the Scout people are always looking for master cylinders too.

 

Thanks kamel for the info. I'm not going to tackle a m/c re-build so don't need the kit part number. BTW, the guy in Turkey is still on eBay and has the Wagner kit but I think it's for the single-cylinder version now. Turner's site has the m/c for $179, but his eBay site has it for $50 less. Also found it at Kaiser Willys for $139. Going to go out to Collins Bros. Jeep tomorrow and see if they can give me any more insight before pulling the trigger on a whole new m/c. If they give me a way to repair/cure what I have now I'll post the info. Just seems a crying shame to have to replace the whole shabang when the push rod attachment is the only thing wrong.

 

Kamel,
That's good to know, that the repro MC available are indeed the step bore design. I had considered buying one for my Jeep, but I was able to get it to work satifactorily with just a good cleaning and reassemble with the same piston seals. I bought a kit from Napa that was supposed to be correct, but it was for the single bore size master cylinders that fit 72 and up. I did use the outer boot from that kit, cost me $35 just for the one usable part.

Don