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Here's one for you guys - my mate has a 91 TDX coming in tomorrow, with the strangest brake problem he's ever heard of. Going forward, the brakes work fine, but in reverse, owner says there is no brakes. Any ideas?
Here's one for you guys - my mate has a 91 TDX coming in tomorrow, with the strangest brake problem he's ever heard of. Going forward, the brakes work fine, but in reverse, owner says there is no brakes. Any ideas?
Oddball answer to oddball question.
There's a vacuum servo valve which is energised to dump the waste gate on the turbo when reverse is engaged. This is to stop the turbo running up when you are in reverse and planting you into the wall a hell of a site faster than you bargained for !
Now, if the end of the servo valve is not connected to the actuator on the turbo, or the actuator diaphragm has a leak, the vac servo valve will open to atmosphere when you engage reverse, totally destroying the vacuum which the brake servo uses to make the brakes work well.
Wierd brakes
I used to get this problem on my old F20. Can't think why it would affect discs on the front but look for just one seized piston on each of the rear brake cylinders. Leading and trailing shoes are the other way round when going backwards and the side of the cylinder which does the least work seizes first. When going backwards you are now relying on the siezed side of the cylinder and the other shoe to do most of the stopping.
I've no proof that this is the cause but whenever I had this problem freeing off the cylinders always improved it.
Al.