i’ve incurred soft brake pedal over time. Upon inspection nothing is leaking and the pads and shoes while somewhat worn are not quite ready to be replaced. I would like to bleed the brakes to stiffen the pedal. Since I haven;t done something like this on a car in forty years any tips or suggestions would be appreciated
If the car has ABS brakes things get tricky. Not as easy as 40 years ago.
No abs brakes
it may go without saying but i soak the bleeder valves with penetrating oil, because they can be stubborn. sometimes a gentle tap with a hammer may loosen a rusty valve as well, but i mean gentle.
Bleeding the brakes will help if there is air in the lines, then you need to wonder how air got into the system. If you step on the brakes and the pedal keeps going down, you need a master cylinder, do the bakes come back if you pump them? Master cylinder.
edited spelling errors.
Blow $20 on a repair manual from an auto parts store. It has the procedure including the order of the wheels. (Often it is RR, RF, LR, LF).
There are quite a few methods. The manual will probably tell you to do the old stand by of having an assistant on the pedal while you loosen/tighten the bleeder. Lately I have become a fan of gravity bleeding (you just loosen the bleeder & let it drip) because its so easy and effective. Its slow but I’m just doing it while doing other things.
Always keep a close eye on the master cylinder level!
It probably won’t mention penetrating oil, though that’s a good thing to use if there’s rust around the bleeders.
Of course, you do need to consider the possibility that your soft pedal isn’t from air in the lines at all. Old flexible brake lines get weak over time & can balloon out under pressure; the master cylinder might be showing signs of getting leaky; rear brakes not adjusting… You didn’t say what year the van is, but its an Aerostar - so its old. I’m betting that air in your lines isn’t the issue. But if your brake fluid hasn’t been changed in a while, go ahead & do it anyway & bleed a lot at each wheel until the fluid starts to clear up.
The pedal does not keep going down it bounces back its just “soft”
It could be rubber brake hoses gone soft.
Good thought, do the lines visibly swell when you hit the brakes?
edit If the hoses are soft?
If nothing is leaking then air is not in the system. Therefore no need to bleed the brakes. The best thing to do to get a “nice feel” is to adjust the rear drums. That will give it a higher firm pedal.
Bleeding brakes when there is nothing wrong is a waste of time
Use PB Blaster to loosen the bleeder valves, rather than WD-40 or Liquid Wrench.
I would replace the bleeder valves if the thread or valve seat show spots of rust; they are not expensive. Use anti-seize compound when you replace.
meaneyedcatz — "Bleeding brakes when there is nothing wrong is a waste of time."DOT 3 absorbs water at a rate of about 2% per year. At best, water causes rust on metal brake parts and deterioration of rubber; at worst it turns into a gas (steam) at 212ºF. Brakes should be bleed every several years.
You might want to buy a bleeding pump so that you can do it yourself in a reasonable time. With the pump, it might take a couple of hours. Without a pump; all afternoon. I change brake fluid every 3 to 4 years.
If your car is more than a few years old and you drive in road salt country then an inexpensive air operated impact wrench beginning at the lowest setting where the tool will barely operate and increasing torque slightly as needed can loosen corroded bleed valves. Simply turning such a valve with a wrench can snap it off.
Bleeding the brakes every few years is good to get some fresh fluid into the system as Mechaniker said.
It’s better to use a helper to pump and firmly hold the brake pedal while a second person operates each drain valve. The force of new fluid entering the cylinder causes turbulence that can stir up debris that can then be flushed away via the drain valve. Don’t release the brake pedal with the drain valve open or you will draw air into the system. Drain until you see new fluid.
Keep an eye on your master cylinder to keep it full. Keep the lid on when operating the brake pedal.
You need a short piece of clear plastic hose to extend from the drain valve to an empty food can to minimize spilled brake fluid.
My last car had ABS and I just flushed the brakes as I always did with no difficulty.
@ Mechaniker
meaneyedcatz — “Bleeding brakes when there is nothing wrong is a waste of time.”
DOT 3 absorbs water at a rate of about 2% per year. At best, water causes rust on metal brake parts and deterioration of rubber; at worst it turns into a gas (steam) at 212ºF. Brakes should be bleed every several years…
This is a fact that I agree with and have stated several times on this forum. Since the OP stated he wanted to bleed for a firm pedal this would not say but imply as other posters do that they believe air was introduced, therefore bleeding to remove air. While I stand on my initial comment I whole heartily with you agree that brakes need bleeding to remove moisture to prevent rusted brake lines.