How to Install Fluid Intake Tubes When Replacing Master Cylinder?

73ess · 12-15-2008, 11:55 PM

I'm in the process of replacing the master cylinder on my 73.5 911T. I'm having a challenge reinstalling the two steel fluid intake tubes into the two rubber seals at the top of the master cylinder. Any tips? Is it possible to pull the two steel tubes down several inches from where they are normally? Or are they pretty fixed in position. I can't get a good grasp on them to push them into the seals. Argh?

Any tips would be greatly appreciated!

IROC · IROC's Garage

Oooo...this is a tough one. What I ended up doing was to use a pair of vice-grips to hold the lines and then put the master cylinder in place below them and then squeezed the vice grips and master cylinder together to force the lines into place. Very frustrating, though.

Hopefully someone else will have a better idea...

tharbert · tharbert's Garage

I had the same problem and questions a few months ago. I got on here and read as much as I could. I spent about 90 minutes under that car, pushing, pulling, angling, vise gripping, cursing... Tried as I might, I could not get the $%*^% tubes inserted.

I ended up pulling the non-pressure lines and the MC out of the car and doing it on the bench. I had the tubes inserted in about 10 minutes and the whole thing back on the car in another 15.

One thing is sure, you don't want to damage those little metal tubes. I hear they are expensive and used ones are hard to get.

kodioneill · kodioneill's Garage

use silicone grease on the rubber.

don gilbert · don gilbert's Garage

are you having prob with both are just the rear one that you cant get a grip on. if you dont have very powerful fingers and wrist, youu can unbolt the cly. , move it into poss . to get a very good grip on it and the line, (im sure everything is nice and lubed by now w/spilled brake fluid) and you can get the tricky one on,then screw it back to t;he body

don gilbert · don gilbert's Garage

oh , and be careful, those line are about 100.00 each

tharbert · tharbert's Garage

I don't think it's a matter of force, it's a matter of alignment...getting one side of the tube flare under grommet lip and easing the rest of the flare into position. Under the car, it's nigh on impossible (for me anyway) to see/feel the tube find it's home. I'll avoid the obvious reference to my teenage years.

don gilbert · don gilbert's Garage

no doubt, it is a major pain, even for someone who has put on a few, but it will go on correctly, you will know because u will hear the little "pop" when the lip seat in the grooove in the grommett. my two brothers and i will take turns on a tough one, 914 is even more fun.

73ess · 12-16-2008, 09:56 AM

I placed some brake fluid on the grommets and tried inserting the flared ends of the lines in, but no luck. I'm not under the car though, working from just inside the front left wheel well, with the wheel and rotor off. So that's likely why I can't get a good grip on the line and can't get enough force to insert the line.

I was hoping I could pull the lines down several inches after disconnecting the fluid reservoir in the trunk. But feels like something is blocking the lines after I pull them down about an inch or so.

Right now, I've pulled the grommets out of the master cylinder and stuck them onto the ends of the lines. The flares are sticking outside the bottom of the grommets. I think that's how they were seated on the old m/c. Anyway, thought it would be easier to insert the lines with the grommets already on them, but it seems even tougher.

I guess I'll jack the front end up enough to where I can crawl directly under the master cylinder. Man, if they only designed some kind of quick release setup on the lines, it would make it so much easier for us DIY guys!

vash · vash's Garage

this is the worst gig on our cars...

zen, buddy.. dig deep

Fishman7 · 12-16-2008, 11:09 AM

I just did this and the best way was to remove the lines from the reservoir and install them on the m/c out of the car and then snake them back through, much easier in my opinion.

tharbert · tharbert's Garage

Quote:

Originally Posted by 73ess

I was hoping I could pull the lines down several inches after disconnecting the fluid reservoir in the trunk. But feels like something is blocking the lines after I pull them down about an inch or so.

On my car, the fluid feed lines were tied in an overhand knot under the dash:

It was a simple exercise to pull the looped line through first and remove the knot. Can't say if this was a factory trick but I suspect it was. I put the knot back in during the re-install.

There are rubber grommets in the firewall and floorboard through which the lines run. The lines were easy to remove and thread back through the grommets.

Good luck!

don gilbert · don gilbert's Garage

tharbert, i think sombody has already broken your lines and replaced them with that, i would take the loop out, looks like air would stay in there, the stock lines are 8 -10 mill hard plastic tubing that gets hard and brittle