Sunday, January 12, 2014

Give Me a Brake!

I have worked all week on getting the brake lines and master cylinder installed and the brakes bled and working.  I have not been 100% successful, but I'm working on it.  Before I got to the brakes, I put some weather striping on the doors:




 
 
Then I tackled the brake lines.  We bought pre-bent lines for both the front to rear line, and the individual front wheel lines, but because we are doing a disk brake conversion with a dual-chamber master cylinder, there was some custom bending and fitting needed.  I bought a flaring tool and tube bender from Harbor Freight, but the flaring tool was normal HF (i.e. Chinese) quality and it was difficult to get a quality flare that would not leak.  The brake fittings require this type of double flare, where the tube is first ballooned out and then swaged into a flare:
 
 
 
 
 
I must have made a dozen of these to get three or four good ones, but eventually I got all the fittings and lines connected except for the master cylinder.  I was paranoid that I would have leaks and not be aware of them until I had brake fluid leaking all over the place.  It would not be pretty to have to disassemble brake lines with fluid already in them in order to fix the leaks.  So I came up with a way to connect an air hose to the brake lines so I could apply constant air pressure.  That way I could detect leaks before adding fluid:
 

 

 
I had a lot of leaks initially, but most were caused by not tightening the fittings enough.  A few required new flares.  I tried using one of Carolyn's incense sticks to search for the smallest leaks:


But the best method was to get my ear as close as possible to the fitting and listen for a leak. 

After I was pretty sure I got all the leaks, I plumbed in the master cylinder after first bleeding it on the workbench:

 


Hooking the master cylinder push rod through the firewall and to the brake pedal and the brake light switch was a bit of a hassle, but eventually Carolyn and I teamed up to bleed the individual wheel calipers.  The results have been somewhat disappointing.  The brake pedal travel is too great.  Although brake application starts to occur as soon as the pedal is depressed an inch or less, the pedal can be mashed to within 3 to 4 inches of the floor and will not "pump up" like you would expect with air still in the lines.  It has been a long, long time since I drove a car without power brakes, so maybe this is normal.  The best thing to do would be to drive the car and find out how it works, but we have no engine.  And that has been a good thing as far as plumbing in the lines and the master cylinder because I must have made 50 trips into the engine compartment, and things would have been much more difficult with an engine in there. 

Just to take a break from the brakes, I took on an easier job and installed the rear speakers:







Tomorrow I go in for cataract surgery on my right eye (left was done last year), so I will not be working on the Mustang for about a week.  That's OK, I think I'm ready for a break.