Hey, it seems that the brake pedal on my '89 TII is getting very spongy and actually sinking to the floor when I'm at a stop. I checked the fluid, and it was empty so I refilled it, improving nothing. Maybe a leak somewhere? If someone could help me out or give some advice I'd appreciate it....anything to my TII back on the road

 

Sounds like a leak. Check around the booster and resevoir first and then go to each wheel to see if the calipers are leaking. If you can't find any leaks, then jack the car up and follow the brake lines underneath the car and see what you find.

 

check under the resevoir on the master cylinder itself (where the plastic goes into the metal), mine leaks TERRIBLY from there, in need of a rebulid!

 

Empty, but did you bleed it?

It does sound like a leak, but moreover, it sounds like you didn't bleed the brakes after refilling.

PaulC

 

if the bottle is empty then there will be air in the system and you have to rebleed after you fill it. bleeding it will make it better, but not fix your problem as you probably have a leak, so it'll just emtpy again.

 

If your pedal slowly sinks to the floor then it means the fluid under pressure is leaking out. The most likely place (assuming you don't see an obvious leak) is the master cylinder. There are seals in it to provide the pressure, and if brake fluid leaks past this seal it will simply go back into the reservoir.

 

Hey, thanks everyone for the responses. I found a leak in one of the brake lines, and I think I'm going to upgrade to some steel braided lines from racing beat. Does anyone have experience with these? Do they improve pedal feel?

 

Yes they do...




-Ted

 

Hey, thanks again for the input. One last question : yes I forgot to bleed the brakes so I'm going to have to do that now. How difficult is it? Should I try it myself or just pay the brake shop $37.00? I have no experience with brake related issues or brake systems, but I am armed with a Haynes manual

 

Bleeding your own brakes is no big deal. There are three ways to do it.

First way takes two people. Make sure the reservoir is full, and person one pumps the brake pedal several times and hold it down. Person two then opens the bleed screw on the right rear wheel for a moment until the brake pedal goes to the floor. Person one does not let the pedal up until person two has shut the bleed screw off. Immediately shut the bleed screw then have person one pump the pedal again. Repeat this procedure as necessary until no air bubbles come out when the bleed screw is opened.

Method two requires an expensive tool. This is a pressure bleeder. It works by having a large special tank full of brake fluid under pressure. An adapter cap is put on the master cylinder in place of the lid. The bleed screws are then opened and the brake fluid under pressure from the special tank flows through hoses connecting the tank to the cap and then through the brake system until it is bled. This is used mostly on larger vehicles like bean trucks that have air over hydraulic systems. There is simply too much fluid to move by pumping the master cylinder In these type systems. The master cylinder activates a brake booster which requires either air pressure or vacuum to operate. Trying to bleed these types of brakes by pumping the pedal will damage the booster.

Method three is my favorite. Go to Auto Zone or Wal Mart and purchase a hand operated vacuum pump kit. This kit is designed to bleed brakes and comes with the hand pump, a special jar to catch brake fluid, several sizes of adapters and a length of plastic tubing. The operation of this tool is simple. Use the appropriate adapter to hook the hose to the bleed screw. This hose goes to the special jar, and another hose goes from there to the pump. Fill the master cylinder reservoir with fluid, go to the bleed screw and crack it open slightly. Attach the adapter to it an pump a vacuum. This will pull fluid through the system and bleed it that way. These pump kits run around $25.00 or so. It is handy for any number of uses as well, so it is not a waste of money in my opinion.

Which ever method you use, start by bleeding the wheel that is the greatest distance from the master cylinder. Then the next closest, etc. until you are finished.

 

There is another option. K2Rd sells speed bleeders, they are replacement bleed screws, with 1-way check valves inside them

 

Copandengr,

I agree with your options, although it's very very important to get a good seal on the bleeder, or you'll pull air around the bleeder.

PaulC

 

Also with option 1, if you run a tube from the bleeder into a jar with some clean brake fluid in it you won't have to worry about closing the bleeder between pedal pumps. Just make sure you keep the tube down in the fluid so no air goes back up the tube.

Also remember, there are 2 bleeder screws on each caliper, use the one on top just to be safe.

 

As far as a good seal around the bleed screw this is not anything you need worry about. Air is not as heavy as brake fluid. As long as you are pulling a vacuum with the hand pump there will be an onrush of fluid to the screw and any air that gets around the screw from its being loose will simply go into the hose, and not the brake system. Believe me, I have had many years of experience with the vacuum method and have never had any trouble with it.

All you need do is open the bleed screw enough to allow brake fluid to be sucked out. How much this is will become obvious once you actually try to do it.

 

True, but you can't tell when you're getting solid fluid or not if you've got bubbles sucking in from around the nipple. And when you're actually racing, and boiling brake fluid, making sure you've got all the air out of the line is crucial to having good brakes for the next session.

Anyway, YMMV. I prefer the two person method.

PaulC