After returning from Okteenerfest the car sat a couple weeks, and after taking it to Cars and coffee I parked it again but backed in and a few days later pulled out and noticed 2 small puddles , front at rear- cleaned it up them parked the car , then a few days later checked again and it’s for sure under front.
I was initially worried that I had a front crank seal when I thought it was from the back, and I am releaved that it’s not from the motor,
I did all that last year and am proud to say it’s been a leak free motor since then, and I didn’t want to pull the motor or trans.
BUT this is brake fluid, and I can’t really explain why this would suddenly spring
A leak . I replaced all brake lines and the 19mm master cylinder about 3-4 years ago, no leaks no issues since then.
And I don’t have loss of pressure on brakes so I am assuming it’s the supply line so I guess I will be pulling the belly pan to investigate. Will post more info when I get a look just wonder why just now? I know the washer is there under the supply line connection, just weird this started now???


Phil

What MC did you install? There were a small number in the first batch of MCs from 914Rubber that had a problem with the welch plug on top leaking. That area isn't under pressure but can slowly weep fluid. They test for it now so newer ones should be fine. I repressed the welch plug on mine and then filled the recess on top with JB Weld just for extra measure. Car has been sitting for months with no drips.

It’s a 19mm 911 mc I bought from PMB when I got all my new hard lines and soft lines as well, same time that I did the 5-lug conversion- i did have an issue during install getting the supply line seated but once it popped into place it had been dry- I did not put in new supply line so maybe that the issue now? I home it’s not complicated it was a lot of brake fluid and the reservoir is pretty low.

Btw I’m not sure but what should I be putting in, just DOT3?? This is clean no blue tinting to it

Is there any fluid inside on the floorboard?

Not that I could see , but will pull the carpet later and make sure, will jack it up and pull the belly pan today as well.

Just see if it is on the floorboard. If so, a cup seal on the MC is torn and the MC is toast.

Someone else can correct me if I’ve got this wrong, ...

If you’re not sure if you are currently running dot3 or dot4, you can safely use dot4.
Use Dot5 only if that’s what you have in it now.

So last night pulled carpet and took a look under he pedal board and no fluid under the
Pedals and m.c. inside, so next is tonight I will try and get car jacked up and pull the cover to steering and m.c. . Btw brake pedal is firm with no loss of pressure so I am expecting to see a leak at the supply line - More fluid on the floor after it’s just sitting for a few days so it’s just leaking out from gravity.

@DRPHIL914 ' post='2753114
So last night pulled carpet and took a look under he pedal board and no fluid under the
Pedals and m.c. inside, so next is tonight I will try and get car jacked up and pull the cover to steering and m.c. . Btw brake pedal is firm with no loss of pressure so I am expecting to see a leak at the supply line - More fluid on the floor after it’s just sitting for a few days so it’s just leaking out from gravity.
[/quote]

You may need a mirror and flashlight to inspect the top of the master. My bet is a leak around the input lines.
A cheap cell phone endoscope is helpful to see into remote areas.
Bruce

Phillip - did you install the metal washers under the rubber grommets at the supply lines.

Back when I installed this I initially forgot- had the leak, then installed the washer and had no leak for the next 3-4 years until getting back from Okteenerfest- have you ever seen a supply line pop back out later?

Make sure the lines going in to the MC are fairly straight with no or little angular pressure. The rubber MC grommets allow for the lines to come in at a bit of an angle (very slight), but too much could cause it to leak. You should be able to wipe everything down and then find where it’s leaking from given how big your leak is.

After closer investigation and looking outside at the supply lines tonight, seeing no leak from the master cylinder at the supply or the outgoing lines, I went back in to look closer, and yes there is fluid under the pedals cluster inside....

Outside under MC and on top are dry, just wet at wall where Mc goes thru but really wet under at the low spot here pedal cluster bolts down to floor

Well lines coming down are dry , lined up fine- BUT Mc will be replaced before car is driven again it looks like but this MC was new less than 5 years ago- hey Eric Shea, is the still under warranty?

I'm certainly no expert but it sounds like it went bad. That's what kills the pedal cluster. Brake fluid on the oem plastic bushings.

Has anyone installed one of the MC from 914rubber?? $145 is about half of a new 19mm ATE,

I few have Ian made a video. Spend the extra couple of bucks and do the easy install, may save a few swear words.

https://www.youtube.com/watch?v=N6ZHK5f_9bE


https://900designs-container.zoeysite.com/1...er-cylinder-2-1




Or save a few bucks and install the URO one.

I gave Ben/MB911 one of the two I purchased. I think he was waiting on a couple banjo fittings to connect it all up.

It might just be the grommets which can be replaced. I would have a new master and a pair of grommets ready.

No fluid on the bottom of the cylinder is indicative of a leak internal to the unit. There is some bleed through on the edges, but my money is the pedal cluster. which hopefully hasn't been soaking in brake fluid. I'm sure Bruce can attest to the damage of brake fluid on the many pedal clusters he has seen.

thanks for the info, I took a look at the video on the install, and I do think I like the idea of getting rid of having just a grommet. sucks that I have a MC that was installed less than 5 years ago and here its leaking this bad. That seal should not have failed this soon. I have 4 vehicles that are 13-15 years old that have not had to have a master cylinder replaced. in fact the last one on the 914 was replaced it was 20 years old and had been sitting, but this should not have failed so soon.

will be placing my order for the new MC today - already did all the hard and soft lines when I did my suspension and that MC , all else look good. but I have to do a lot of clean up to get the fluid out, I probably should pull my pedal assembly- it was rebuilt back 5 years ago, but should I get one with new brass bushings etc? -

Phil

mark,

placing order and wondering if the Okteenerfest 914 discount code is still viable and if so can you PM me with details.

Phil

yes master cylinder has failed. As much trouble as they are to replace I would purchase a new fte or ate cylinder and install after cleaning up the pedal cluster area of brake fluid and resultant debris and bleed thoroughly with ate brake fluid. The 19mm master cylinder is not that expensive can be bought for 220 at any of the usual suppliers, and is well worth it. 914 17mm has been discontinued

I agree doc, need to get that brake fluid cleaned off the floor and the pedal cluster- in just a week or 2 the fluid that leaked thru the floor had already melted away the paint and primer on the floor pan , so lots of clean up . ATe fluid do you mean the dot3/4 stuff synthetic? will have to flush the whole system out anyway I figured. .

Yep good to the end of the month. Just PM me if you have any issues using it.
Mark

Mark,
first of all thanks for the super fast shipping on the MC! it arrived yesterday and I hope to get at it tonight or atleast this weekend. My gas tank is in so I will have to work the lines around that, with the new fittings on top there will not be much room above the MC to the gromets where the supply lines come thru so in order to splice these into place it looks like I will have to trim those off at the bottom after pulling the supply lines back up and into place,
I watched the install video and looks to be fairly straight forward, only other thins is I guess if my tank was out I would probably look at putting new supply line in even though these look ok they are the old original ones, I didn't know it this is a specific type of plastic for brake fluid?
anyway, tell Scott thank you!

Phil -
will post some pics when I get on to this.

I did get this project partly completed last night, taking out the old one was not that hard, about 20 minutes to get it pulled out, and once out of course you can see the front seal was leaking , as evidenced by the fluid inside the car.
I ordered the 19mm new MC from 914rubber which has the threaded connection on top so you can clamp the new lines on. it is up and in place but not fully connected yet, due to lack of time(prior commitment) , but I should be able to connect the lines tonight in just a few minutes.
my biggest issue is that I am doing this laying on my back with car on jack stands, and its a bit tight in there with the steering rack in place etc, would be easier with at least a scissors jack tp get it up higher, I now have a knee I cant bend very far due to a torn meniscus so it gets tricky trying to bend and roll around under a car

I hope this MC and the seals last longer than the last one, because 4 years is NOT long enough, I hope I don't ever have to do this job again.

Yes, mush easier job on a rack, If you need new lines we can supply. They are not formed, but may make the job easier.
Thanks,
mark

Also,
On the old one after yo get this done. Can you post up some pictures, I'm curious as to how it failed, any good seal should have lasted at least a decade. Wondering if there may have been a contributing reason.
Mark

will do. from first glance last night I pulled off the front rubber thing and you can see the fluid was leaking out front, not sure what you call it but as the brake pedal is pushed you push the rod into the MC and it compresses or pushes in the xxxx( plunger?) that would compress the fluid and cause the caliper to grab, well every time I was pushing on this it was coming out around that seal onto the floor around the pedal assembly, this started at some point during Okeenerfest or right around when I got back, at least that was when I first noticed the puddle in the garage, and heavy use on the mountain roads really got it going I guess.

PHil

I would assume this could be rebuilt and a new seal installed? if so how hard is this to do? is this something you do Mark? or PMB?

it is a 19mm ATC 911 MC

Good luck finding the kit for it. MC kits were readily available for all cars in the 70's & 80's. Also. this isn't something you'd want to tackle w/o some knowledge of how to do it. First you had to determine if it was rebuildable. If the bore was pitted or scratched the MC was junk and red tagged. That being said, I rebuilt a pitted MC on my 56 Chevy a couple of times in a 2 week period just to keep me on the road until I could buy a rebuilt one.

There were kits in the day. However, it is up to the re builder to get it right, and there are some issues that can't be fixed.

Not really worth the time an energy to rebuild as many are too far gone.
Just out of curiosity is it an ATE? Should be a stamp on it.

mark

Google.... Or I used duck duck go now, but search for 911 master cylinder rebuild kit. tons of them. surprised we haven't gotten the "it's your safety" comment. But it would be nice to have one on the shelf for next time.

95$ here:https://www.aasesales.com/products/da3c-b52...e4626&_ss=r

Interesting,
We could on the next run do up extra parts and make rebuild kits for MUCH less.

I started to google that right after posting that but did run across Pelican and Stoddards , some sites I cant access here at work, so I have to wait until I get home, but it did seem a bit pricy for what you are looking at to rebuild these.

its interesting that my first MC failure had no leaking but internally no longer was able to hold pressure, and I think this is the most common failure.

This one failed by leaking out with out actually loosing any pressure or braking function so I didn't have a clue it was happening until the big puddle appeared in the garage floor.

- pictures tonight!
Mark, if you do a rebuild kit I would think this would pay off over time .

I have no idea where the parts in these other kits are sourced from in other words, where are they and by whom are they manufactured? AASE, Stoddard, Pelican, and AA have the kits but who makes the components?

I would like to rebuild this one that failed and have one on the shelf just in case of future failure of this new unit I am installing.

I have a 1500 mile master cylinder that needs a seal kit. I've rebuilt several master cylinders over the years (not in a long time though) without any trouble, even way back when I was a total newbie 40 years ago, but there are master cylinders that can't be rebuilt.

I do understand why kits aren't available, but IMHO (and with all due respect to our good vendors) it's mostly legal BS that keeps rebuild kits off the shelf. I don't think I'd sell them either, due to the old 13 1/2 theory.

There you go. I suppose it would not be good to "include a rebuild kit" with you brand new MC...

5 hours , MC in, pedals removed floor and pedal cluster cleaned up and reinstalled - that had to be done , that was about half the install time, the other 2.5 was fighting with the hose onto the new fittings and getting it proper and tight- in the end, it looks ok but

It has to come back out! Major leak from between the new fittings and the MC- the supplied o-rings are not doing their job and that really sucks. I had a feeling about that when I first installed the new fittings as I had a hard time keeping those o-rings from squishing out, I should have listened to my gut at the time and called 914rubber about the o-rings possibly being too big- now it has to come out and I have wasted my whole afternoon.

So that’s it, I and not going to have the car at car show next Saturday or the cruise in on Thursday. I don’t have another afternoon or night between now and then to Fuchs around with this and re-do it.

BTW, this took longer to do than the last time with just pressing the grommets and lines in place but I figured what the heck, let’s do this it should be leak proof and never mess with it again-

I think the design itself is fine, but not the thing to be doing if your steering rack is still in and you are lying in your back under the car. But MC was shot so it had to be done.
Well maybe tomorrow I will pull it and see if Lowe’s has an O-ring that will work ,but I may be more frustrated right now then I have really ever felt doing a repair on this car.

I need to go take a blood pressure pill I think I am going to blow a gasket

Here is the MC that came out , leaking from front seal

Another view

I will probably order a rebuild kit for this .

Drop me a call tomorrow. You do want to put the abrasion netting on the cloth hydraulic tube nest to the firewall. Not sure why it's not there. Hopefully you got it in the kit. The shorter nipple will also be the one at the firewall if yo have the 2 sizes. We have just started making the one shorter size to remove the possibility installing backwards. The seals are Viton, and do crush down. Should only be one size on those.

Mark

O-rings are too big I think is the problem- I was very careful to try and keep them in place as they compress it either they are too soft too big or both to not stay in place and make a good seal when tightening them.

I only got ones size of fitting both are the short variety, but that seems to be fine.
Netting was left off by accident , I will probably put it on when I pull this out to re do it.

If there is a pipe thread tape, like plumbers tape that will hold up to brake fluid I think that would be smart, it would seal the threads better than just the o-rings.
Also barbs on the nipples would help keep hose on while trying to get it installed .
Anyway will talk to you tomorrow.
Only question I have also would be about the orientation of the hoses. Does it matter which goes to the front and which to the back? Seems both are low pressure one supply and one return, I don’t know which is the in and which is the out, but I would not think it would but I’d like to know if it does, will have to recheck this on mine.

Spoke with Mark and we are pretty sure the wrong o-rings are in my kit, but also felt that we could retry installing it by using Teflon tape on the threads, so I did this and reinstalled fittings, after fighting with the hose clamps getting them tight enough to keep them from popping off is an issue with the hose due to the lack of flexibility of the hose.
I would do this next time with a different supply hose, something a bit softer and more flexible would make this process a LOT easier. But I can tell you the third time taking this out and putting it back in went pretty quick, by that I mean about 5 minutes to loosen and disconnect the lines, pull MC, reinstall and connect 5-10 min only BUT fought the Dan hoses and trying to get them slid back onto the nipple took 15-20, .if not for that I’d say I could do it again start to finish total in less than an hour- now bleeding the system will be the next step so I hope we can get that done tonight.
So far no more leaking or seeping past the oring and the tapes threads.