Brake problems

[76tr7rules]

Turns out I have more going on than I thought. Here is what I have done so far, I replaced the wheel cylinders, hardware, rear shoes, rear hose, and front calipers. I just finished putting the new front calipers on. I reused the old semi metallic pads that were on the car because they had about 90% pad left.

The issue I am having is some times the brake pedal is high and tight and other times its easy to push the pedal until it gets half way to the floor then it gets very firm and solid. Please dont confuse what I am saying with the feeling you get from a bad master cylinder where you put mild pressure on it and it slowly sinks to the floor, or you push it and it goes to the floor then step off and next push it feels normal again. It does none of those things. It almost feels like the rear shoes are set really loose or there is a ton of air in the system. Ive bled the brakes until I got fresh fluid and no bubbles from each caliper and the one wheel cylinder in the back. After bleeding it and adjusting the shoes as tight as I could and still get the drum back on, the pedal didnt get tight until it was half way down. Then I started the car set the emergency brake went inside while it warmed up came out put the brake down and noticed the pedal was high and tight. Took it out for a ride, the pedal stayed high and tight for the whole 20 minute ride (even in traffic), and as a test I locked the brakes up 3 times no problem. Then I came back home and got my dad we went out and I took him to the store, we parked the car, I set the Emergency Brake, and we came back out about 5 minutes later now the pedal is half way to the floor again, and remained that way the whole way home. When it gets that low I cant lock the brakes the car just slows down to a stop. I tried pulling the emergency brake up and then putting it down just to see if the pedal would get firm again and it didnt. Is it possible the rear brakes are becoming unadjusted from the pressure of the Emergency Brake? Also I know On an American car if you put the left side adjuster on the right side they wont adjust, is that possible with the Triumph?

Tell me what you guys think this is all thats keeping me off the road, and I really want to figure this out.

[nick]

With parking brake set will the car move when you let the clutch out?

[img][IMG]http://i615.photobucket.com/albums/tt234/nickmi/TR7%201975/Yellow.jpg[/img]
nick
'79 TR7 DHC
'76 TR7 FHC

[76tr7rules]

No it wont. It will stall the car. It also is fully engaged with like 4 clicks.

[jclay (RIP 2018)]

OK, you still haveair in the rear portion of the brake system. When you park the car, the heat builds up in the rear cylinders and the air in the system expands. It can get so bad that you loose all braking. Get a set of speed-bleeders and a gallon of brake fluid. Loosen each bleeder 1/4 turn, and start pushing the brakes down. There is no need to open and close the speed-bleeders, just have some one to keep adding fluid to the master cylinder. You can put hoses on the speed-bleeders and let them hang into empty jars so things won't get messy.

http://www.jclay.me/jclay/Rear_Brakes.html

[url="http://www.summitracing.com/search?SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=speed%20bleeders"]Speed-Bleeders[/url]

Clay

[url="http://www.jclay.me/"]My Triumph Site[/url], [url="http://www.triumphtechnical.me"]Technical Stuff[/url], [url="https://docs.google.com/folder/d/0B8MWEvqOpX3udEF4SmFQUW9RS09hbU5uNW5Wd0xrUQ/edit"]My Public Folder[/url],

[76tr7rules]

I think the master is just leaking actually. I pulled it out today and it was rusted to the servo. I tapped t with a hammer each way and then eventually got it off. The back of it was all wet with brake fluid not a tremendous amount but enough to think I should at least swap it out. If anything Ive removed a 36 year old part from my car and made it safer. I'm going to apple hydraulics in the morning to pick the new one up. It a rebuilt with a brass sleave and its still only 145 compared to 280 like everyone wants for a new one...

[Hasbeen]

Yep could be master cylinder.

It could also be the booster.

To check it, with the engine stopped put the brakes on firmly, then start the engine. The pedal should sink about an inch or so to the floor as the vacuum applies the boost pressure.

If not, check the vacuum hoses for a leak that could be intermittent. If it's doubtful, remove a hose from the carb/manifold, & suck on it to make sure the diaphragm is sound. If you can suck air, you have a problem in the hose or booster.

Hasbeen