Replacement Brake Master Cylinder Lacks A Sleeve Shaped Push-Rod Guide

Here is the replacement that I received.

Thanks for the reply! I might have my terminology mixed up but what I believe to be the pushrod is depicted below. A new one of these was sent with the replacement master cylinder and the old one is still on the car in the booster. The sleeve extending out the back spins in place but does not seem to come out of the old master. It slipped over what I am referring to as the pushrod. Is my terminology wrong? Should the "sleeve" come free of the old master? Thanks again for the help!

Evan

Another view of the "sleeve".

Master Cylinder Instructions ?  I recently got a new mc  and  have the same situation as PANTHER351 ,, the reply was to use the old pushrod .. But  that sleeve doesn't come out , it's part of the piston . If anyone could clear up how exactly to install this master cylinder that would be great , Thanks 

The master cylinder changed over the years, maybe 3 versions, I am not familiar with all the differences, but would assume the sleeved version to be an early one. to center the rod. The last photo shows the internal circlip that needs to be removed to get the sleeve out, but as later variants did away with it and had a cupped piston to center the rod you likely don't require it.

Thanks for the reply , what a great resource this is . Ill try to be more detailed . First those pitchers are from another member but are exactly what I bought and last picture is what i removed . That sleeve does not come off the snap ring holds only a flat washer and seal, that sleeve is actually part of the primary  piston and only comes out the other end after removing the stop nut and a well hidden retainer under the reservoir rubber seal that resembles a mainjet in a carburetor . So can't use that , but because the sleeve -well is a sleeve the seal orifice is way to big , I also was thinking there would be a (stock) rod length issue without the sleeve , probably why the new one came with a rod ,,,,,, hmmm sounds like Im answering my  own ?,,,,     But  I would like to be certain about whether to remove the original seal, is that black rubber washer the replacement seal and process of  doing it , Thanks again .Ledphoot

That is a cheap chinese rip off. The original master cylinder is different and still avaiable in Europe. I got mine from Roland in Hamburg.

 

Well sh-t ! I hate to say (ask) but here goes ."So will it work . with proper installation ? "  Also do you have a webb address and or part # for the sight your taking @ . Thanks for the input I appreciate your time . 

Send an email to detomaso@gmx.com. Roland knows his stuff.

Thanks 

Agreed Roland knows his stuff, but this is the first time I have seen a master cylinder with the sleeve. I am not quite sure how you can tell the one in a bag is 'cheap Chinese rip off' from the photo though!

Hello

I also bought the one in the bag and I confirm that it is of poor quality (especially the brake fluid reservoir) but must work, but I preferred to buy from superformance.co.uk a very good OEM copy ref: 308 Right Hand Drive 30806095 (£ 269.95) that I mounted on my pantera and that works very well.  You just have to get your old brake fluid reservoir and put it on the new brake master cylinder.

Re quality ? As of right now,visually and holding it , the overall impressionist seems to be ok, but  without actually performance testing it , might be a gamble of time and effort . In the past Iv bought things from china because the price was a fraction of the genuine part , of those mm?@ 85-90% worked out ,, But !,,,  the parts that didn't , failed  because of poor quality rubber , so idk ? Im gonna definitely ask  Mr Roland , go from there , . Isn't it great when you buy a part , open the box and it looks exactly the same , and bolts right  on ! Could happen ?Thanks for all the help . 

All original master cylinders have the sleeve. It is a guid for the pushrod. Inside the bonaldi brake booster is no guide for the push rod.  There is only a little Cup that holds the Bottom of the rod in place. Imagine, what happens if the rod jumps out of the cup, it will fall square and then? …….. happy braking!!!

 

Hello , I just got back to the Ponderosa ( home )  . Was away for a few . Re sleeve , ya I totally see the issue , that's why Im not getting how the replacement fits , or how to make it fit . Waiting to see what Roland has to say . Thanks .

Gentlemen, I am in the same boat, having ordered a master cylinder from one of our reputable vendors many months ago. When I received the new master cylinder, I just set it aside, waiting till I was ready to install it. I am still not ready to install it, but after this topic came up, I went back and looked at what I received and found that I had received a new master cylinder without a sleeve and a new pushrod which was shipped loose. When I looked at a couple of old master cylinders that I picked up over the years, they were sleeved! Since the sleeve is supposedly very difficult to remove, I too would be very interested in how to resolve this problem! Any additional information that could lead to solving this problem would be greatly appreciated! Thanks!

Bill

 

 

Ok Bill , here's some of what I've found out having bought the same part , it's possible to get a replacement w sleeve from a vendor in Germany . Haven't yet found out if what we bought will work as is . I don't think so for a couple reasons . So what I did is took the original master apart , removed the sleeve , cut it off the primary piston then ground the end down until it fits nicely into the replacement master that I bought without the sleeve .If your interested I could be more detailed on what I did . Haven't yet installed it . What I didn't do before taking the original apart was measure how far the sleeve sticks out from the body of the master . Perhaps you could give me that number if you've got a original around .Thanks 

Thanks for the info LEDFT and yes I would be interested in hearing more details. I will get that measurement for you this afternoon.

Thanks!

Bill

LEDFT,

Attached are two (2) photos of the sleeve measurement that I took a few minutes ago. The distance from the top edge of the sleeve to the top of the metal plate beneath the circlip measured 1.930 inches. Hope this helps!

Thanks!

Bill

Absolutely , thanks . Ill try to get you the details today   Thanks again 

 I haven't tested this yet , just fyi.   I disassembled the original master ,to do that pop the reservoir off, pull out the rubber seal out from the secondary feed port , looking down into that hole there's what looks like a main jet , get a flat head screwdriver remove it , remove the end cap and everything should come out of the master . Next I cut about .25 inch off the piston end of the sleeve (not sure was necessary ) then without grinding the "sleeve" I carefully reduced the circumference until it slid into the new master .

LEDFT,

 

Thanks for the info! It will be a while before I do this work, but the information you provided will be extremely helpful. Thanks again and good luck with your testing of the unit.

Bill

Bill - Results-  , working the sleeve until it matched   the measurement you supplied, brakes work really good , better than I ever  remember .  Have only driven it 8-10 miles , but brakes feel good , so the custom fit sleeve works no doubt and wasn't hard to do.

LEDFT, thanks for the update! I am glad everything worked out. I will definitely be looking at doing this to my MC as well!

Thanks again,

Bill

LEDFT, well I am finally ready to install the new brake cylinder and brake booster. I had a few questions after looking it over carefully and I am hoping you can help me out. The new master cylinder is longer than the original and I had the following questions:

1. The new master brake cylinder has two ports along the cylinder with a bolt located between the two ports. Do you know what the bolt is for?

2.  Did you use the new push rod supplied with the cylinder?

3.  Did you use a new brake booster or the old booster? I purchased a new booster and it came with a new push rod as well, only slightly smaller than the one supplied with the master cylinder.

4. Did you have to modify the rubber seal slightly to allow the sleeve from the master cylinder to pass through the seal on the booster?

5. Did you have to rework the two brake lines to fit the new master cylinder since the new cylinder is longer than the original?

6. My new push rod OD that came with my cylinder was actually larger than the ID of the sleeve(0.432" push rod OD vs. 0.4145" sleeve ID). The new push rod OD that came with my new booster was 0.3745" OD. Did you reduce the diameter of the sleeve a lot? Do you remember the diameter of the push rod you used?

7. Just out of curiosity, do you know how to easily remove the master cylinder reservoir? I tried but it didn't move much.

8. Since the original reservoir has the fill cap on the front of the master cylinder and the new master cylinder has the fill port on the rear of the cylinder (windshield side) , did you reorient the reservoir so that the fill cap location matched the original cylinder?

I know have asked a number of questions, but any information provided would be greatly appreciated. I have also attached some photos of the new and old cylinders for your review as well.

Thanks so much!!!

Hi gvillbill,

1. the bolt between the two ports hold the secondary piston in place, only remove it to replace the pistons seals (see machining in the secondary piston).

2. the pushrod must be adjust with a clearance 0.035 to 0.045 in (see attachments)

7. you have to pull hard enough to remove the tank because it's clipped into the 2 seals, to put it back, I put rubber grease to facilitate reasembly

8. fill cap orientation doesn't matter

sorry for my bad english.

Thank you for the info and the photos. I appreciate it very much!

The larger reservoir feeds the front brakes.  The orientation of the reservoir on your new master cylinder is correct.  It looks like it was installed backwards on your old master cylinder.

I think that the orientation of the reservoir on the old master cylinder is correct see pictures from 1979 advertising brochure and the vintage photo

Hope you got the info you needed . I received so much junk mail re the
midterm elections , I saw a post from today the earlier ones were 3 pages
back ,,,,, Anyway I used the old push rod and made the sleeve work from the
old master. What I did worked for me and has been since , But, to say I
am not qualified to advise someone on their "Pantera" braking system ,
would be an understatement. Maybe there is a reason(from someone who is
qualified ) why what I did is not a good idea .

On Sun, Nov 20, 2022 at 7:07 AM The De Tomaso Forums <alerts@crowdstack.com>
wrote:

Thanks to everyone who responded. I really appreciate the responses.