Stiff brake pedal after brake bleed/line replacement

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Tom4444
Posts: 127
Joined: Jan 21, 2022 11:42 PM
Location: Virginia

Stiff brake pedal after brake bleed/line replacement

Post by Tom4444 »

So had the brake lines and fluid replaced and now the brake pedal is really stiff.

It improved somewhat after the bleed by repetitive pressing but that initial “soft” bite of the pedal is gone and it’s pretty hard to press and that linearity of the pedal is gone.

The shop doing the bleed said they were unsure as to the cause, but it could be the brake master cylinder. However there’s no leaks coming from the cylinder.

I was doing some reading on the forums and it looks like it could be the pressure accumulator.

Should I just swap everything out or start with the accumulator and brake switches since they don’t necessarily require me to rebleed the brakes?

Any other thoughts to triage this would be appreciated. Or a way to narrow down the cause.
Blue Shadow
Posts: 10195
Joined: Feb 12, 2006 12:00 PM
Location: SE PA

Re: Stiff brake pedal after brake bleed/line replacement

Post by Blue Shadow »

Brake switches are just switches to illuminate the dash lamp when needed. If not leaking and they work let it be.

The bomb is either good or bad. No reason to replace a working bomb

Turn off car. Check power fluid level, it should be below the dished screen. Press the brake pedal 15 times and the level should rise to 10mm below the rim of the reservoir. This is for a working bomb. A non-working bomb will have the fluid level about 10mm below the rim of the reservoir without pressing on the brake pedal and pressing the brake pedal will not change the level. Remember this is with the car off.

Additionally, a bad bomb will flash the brake light on most brake applications as pressure drops before the pump brings it back up to within spec for the light to be out.
Last edited by Blue Shadow on Sep 27, 2022 1:18 PM, edited 2 times in total.
Tom4444
Posts: 127
Joined: Jan 21, 2022 11:42 PM
Location: Virginia

Re: Stiff brake pedal after brake bleed/line replacement

Post by Tom4444 »

Pedal does not have normal pedal feel (soft initial press gone) under normal driving and the pedal is rock hard when the car is off.

There’s also trouble getting fluid through when bleeding.

Shop thinks master cylinder?

Can it still be accumulator?
Blue Shadow
Posts: 10195
Joined: Feb 12, 2006 12:00 PM
Location: SE PA

Re: Stiff brake pedal after brake bleed/line replacement

Post by Blue Shadow »

I explained how to determine if the bomb is good or bad. But maybe I didn't say the bomb is the accumulator.

Check the function of the accumulator as stated and report back.

I guess it could be the acc. But since you can check it as working/not working seems that would be the thing to do.
Tom4444
Posts: 127
Joined: Jan 21, 2022 11:42 PM
Location: Virginia

Re: Stiff brake pedal after brake bleed/line replacement

Post by Tom4444 »

Don’t think it’s the bomb.

I depressed pedal as instructed and didn’t notice any signs of a bad accumulator

In fact I pressed really hard on the pedal that seemed to “normalize” the pedal and give way bit and brought back the slightly soft initial brake feel while driving. Wasn’t the same level of softness as my other cars though. Tough bc I don’t have a point of reference bc I only had the car for a week before it went to get fluids and ppi etc done.

I might just keep an eye on this and see if it worsens or improves before replacing parts unnecessarily.

Thanks for the help!
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