Rear Brake Question

Topic: Rear Brake Question (Read 1911 times) previous topic - next topic

Rear Brake Question

March 13, 2005, 07:52:31 PM

My '83 T-Bird is use for drag racing. When factory stock, I could not get the AOD stock convertor to stall more than 1100 RPM's before the rear brakes would not hold the car. A change to a 3000 RPM stall convertor now allows me to stall to 2000 RPM before the brakes can not hold. The power booster was checked per the factory manual and passed the test, but when I pump up the brakes at the line I feel a metal stop at the bottom of the pedal stroke. Rear shoes have been replaced and adjusted up for slight drag on the drums. I have a 4.10 gear rear end (Trak-Lok). Am I wrong in thinking the brakes should hold the car on the line better, I.E. 2500 to 2800 RPM's, before being overpowered. This is with a stock 3.8L at about 150 hp. What am I missing? Front disc's work O.K. and the car stops fine from 85 to 90 MPH at the finish line. Anybody got ideas? Thanks, Fred

Re: Rear Brake Question

Reply #1 – April 20, 2005, 06:37:15 PM

For those of you that followed this thread, I found the problem. I'm relating the fix because you should look at your brakes also, if they haven't been inspected lately. All three brake hoses were bad, By that I mean they would flex enough to reduce pressure a 200# or more at the axle. I found no leaks or friction materials problems, but a through flush of the system turned up very bad fluid condition. If you have a 22 year old car, check those brakes out before you have a problem. By the way SS hose from Russell won't work on T'Bird/Cougar. The cross reference numbers are the same for Mustang (79 to 86) but believe me they are not the same. The bottom line is the car will now stall to 2800rpm's against the brakes. As soon as the snow stops I'll head for the track. It just might make a difference. Fred

Re: Rear Brake Question

Reply #2 – April 20, 2005, 07:12:05 PM

There's another thing that will let your tires spin easily... your tires. Glad you found and fixed the problem though. How fast have you gotten that 3.8 to go? As for the lines, you should be able to fit Mustang calipers on with no problems. Or find an adapter. If you still have the SS lines... that is. ^_^

Re: Rear Brake Question

Reply #3 – April 20, 2005, 10:34:10 PM

Darkthunder, The rear hose is different. It has a "banjo" bolt type of connection, where as the T'Bird is fitting to fitting type. My rear tires are M & H Racemaster slicks. Best E.T. so for is 16.3 seconds at 3275 # of weight (read Heavy). The motor is box stock, with the exceptions of Isky valve springs, and a Holley 2BBL carb. Suspension is tweaked, trans (AOD) has shift kit and a 3000 rpm convertor, Mallory Ignition, Line Lock, 4.1 gears and a TracLok diff. It's a very inexpensive ride so far. Because of the brake problem I had backed off trying the obtain more HP due to the low RPM leave on the tree. Now I can see about some more ponies in the future. Car is deadly consistant but the driver sucks. If I don't get better, I'm going to have to fire myself. Fred

Re: Rear Brake Question

Reply #4 – April 25, 2005, 11:28:25 PM

Yeah I had one of those hoses, gave it to a friend of mine to use on his Mustang. Considering I had to modify the front to fit (cutting, double flaring and bending...) makes you wonder why I didn't do the same for the rear. *shakes head* Those times sound pretty good, seeing how my 'lighter' Mustang 3.8 prolly wouldn't break high 20s in the 1/4. Good luck with it. Sounds like a fun car.

Re: Rear Brake Question

Reply #5 – April 26, 2005, 12:57:18 AM

Quote

16.3

thats pretty good. the second tbird i had ran 15.8 with the 5.0 SO, pullies, 2400 rpm stall, 355s and shift kit...

Re: Rear Brake Question

Reply #6 – April 27, 2005, 10:05:28 PM

I have high hopes of high 15's with this engine. I'm already doing research on the next motor, but am sure it will be a V6. I'm trying to get the right part numbers for NHRA V/SA. It's got a 15.8 second index, so I hope to get there. I would also like to race at sea level as our track (TopGun) is at 4000 feet. If I can't breath, why should I think the car can? I race this weekend, snow permitting so I'll report after that. Thanks for the encouragment. Fred