Booster Cooling Brake adjusters Brake pedal travel Handbrake failure Hoses and lines Proportioning Valve	Back to MANUAL INDEX Related topics: Joe Gorin's brake overhaul Johan Vorsterman van Oijen's Capri brakes Krzysztow Milik's rear disc conversion

Booster The TR8 booster is a larger diameter than the TR7. The Rover SD1 booster is larger again and provides reduced pedal effort. It is not a direct replacement for the wedge units but may be fitted with some modification. The Rover master cylinder must be used with the Rover booster. The input shaft needs to be extended to mate with the wedge pedals. The larger diameter of the booster also tends to foul on firewall.	[Top] Booster Tip
Cooling A number of wedge owners have reported a reduction in brake fade after fitting ducting directed into the disk rotor. Theory would suggest that the inlets should be located at the high pressure area at the centre front of the vehicle rather than at the sides under the front indicator lights.	[Top]
Brake adjusters I think that the earlier suggestion that the brake adjusters have failed is a good starting point for this problem. If the adjusters are indeed at fault, the brakes should be firm after the slack in the adjusters is removed. The slack is difficult to adjust on the TR7 since the adjusters are a ratchet kind of deal rather than the expanding screw found on most American or Japanese cars. The screw can be adjusted by inserting a tool through a hole in the backing plate, but I think that the adjusters on the TR7 can only be relaxed through the backing plate. This is to allow removal of the drum past the rust ridge that forms beyond the area of contact with the brake shoes. I would suggest that the adjuster on the TR7 be set as tight as possible while still being able to put on the drum. If the adjuster is working properly, it should remove the slack due to wear when the brakes are applied during backing. I removed all of the rust from my adjusters and put a very thin coat of white lithium grease on them when the rear brakes were last serviced. The pedal worked fine afterward, but the car was taken off the road soon after so I don't know how long the fix will be effective. James A. Babcock	[Top]
Brake pedal travel The first time I press the pedal, it travels much further than the second time immediately afterwards. Isn't this a phenomena of disk brakes? Since there is no return spring on the pads, it takes multiple spins of the wheel to push the pads out. So, if you step on the brakes twice in a row, you move the pads close to the disk on the first press, release the pedal, which lets more fluid into the system, then press the pedal again, and there is now less travel because the pads are closer to the disk. Now, "much further" may be another story, but I have always noticed that the second press does not go as far as the first press. I can't quantify how much. There might be a problem, like a broken return spring on the rear drums which is making things worse. Why doesn't the master cylinder "suck" the pads and shoes back when you release the pedal? Ah! the seal is designed such that it lets fluid past it as the pedal returns to its rest position. Peter Reichert If bleeding has been ruled out, the possibility exists that the rear brakes are not adjusted correctly. "Loose" rear brake shoes will rest away from the drum. Pumping will serve to temporarily move the shoes closer to the drum, then real braking can begin. This can be interpreted by the driver as soft pedal feel. One way to check this without actually getting down and adjusting the brake shoes is to apply a few clicks of the handbrake and see if this alleviates the problem. Greg Meboe	[Top]
Handbrake failure The handbrake on a wedge can gradually fail to operate over time as the lever arm at the backing plate to which the cable is attached siezes at the rivetted joint with the shoe links. It may only be evident by disconnecting the cable at each wheel and operating the lever arm by hand with the drum removed. The problem is cured simply with a few drop of lubricant and working the lever arm. In cases of severe corrosion of the joint it may be necessary to remove the arm and link from the backing plate to work the pivot point loose. Philip	[Top]
Hoses and lines Unprotected steel braided hoses may suffer chafing in sandy and dirty environments. The solution is to sheath them in rubber tube.	[Top]
Proportioning Valve Exactly what's wrong with your braking? Are the rears locking up first? Or is the braking just uninspired? If you haven't already done so, replace your front pads with a good semi-metallic set (Repco metalmasters work well and TS Imports has some nice composite pads too). I had a set of new factory OEM pads which were just a disaster right from the start! Next thing to do is replace all the rubber sections of the brake lines. Then, and only then, would I recommend starting to play with the brake balance. The TR8CCA newsletter (and this list) had a lengthy discussion about brakes some time ago. I got a Tilton adjustable brake proportioning valve (Trick Racing Stuff for sure) for about $85 from Dave Bean Engineering. Haven't tried it yet. You can also get an upgraded factory valve from Ted at TS Imports (about $100?) which throws a little more braking to the rears. He also sells an upgraded set of rear shoes for an additional fee. Gary has Ted's upgrade if you wanna know his impressions. My TR8 currently locks the front wheels before the rears (I videotaped it) even with my upgrades. I'm eager to try the adjustable valve. However, new pads VASTLY improved the brakes and I'm no longer quite as motivated about upgrading the brakes (although that may change if I start to autocross a little more seriously). FYI: My brother's TR7 had its prop valve bypassed altogether. We're going to have great fun autocrossing in this car. The rears lock up ALL the time. Not especially good. Easy to swap ends! The adjustable valve is meant to replace only part of the OEM prop valve. Without the OEM prop valve, the rear wheels lock up as the car rotates about its CG and unloads the rear tyres. So, you want a valve to limit the amount of rear braking and, preferably, you'd like an adjustable one (Tilton in my case). So, disconnect the rear brake lines going into and out of the factory OEM valve and run them through your custom prop valve instead. I haven't tried this yet so keep us posted if you do. Jim TenCate	[Top]