Intermittent Brake Booster

[JBurt]

Over the past few weeks my ABS light has come on intermittently. Fluid is good and ABS seemed to work okay on dirt roads. Hadn't gotten further into diagnosing than that but the light went off and I haven't worried about it. Thought it might be a bad connection with a speed sensor.

Then last Wednesday I've started to have a very stiff pedal with reduced braking power. It begain just on cold starts and would go away after 30 seconds or so. I live in the desert so it's never close to freezing but I checked the booster check valve anyways, works fine, so I just cleaned it out and sprayed wd-40 inside. Also the intake hose looks good.

It sounds like it is probably the booster itself, but I thought when these failed they failed incompletely, not intermittently. Any thoughts?

 

[19963.4lsr5]

I did all that to my check valve and ended up replacing it anyway. For all intent and purpose it seemed fine but would act like yours installed.

A new one fixed it.

 

[Paperjam]

Have you pulled a code for the abs?

 

[JBurt]

I haven't checked the abs codes. I need to figure out how to do that. I've read you can use a jumper and make the codes flash. Today the booster failed completely. No power brakes at all. Now the rig is parked until the new booster comes in from DeathCougar. This weekend should see it back in action. If the abs light is still on after that I'll read the codes.

 

[19963.4lsr5]

Did you try a new check valve first? It's not very common for a brake booster to fail.

 

[JBurt]

I removed it at the ball moves with whatever pressure is in my lungs. It seems to work okay to me. Any other tests?

 

[19963.4lsr5]

I removed it at the ball moves with whatever pressure is in my lungs. It seems to work okay to me. Any other tests?

Mine acted the same. I'd suck and blow and still no brakes at startup. Replaced it and presto brakes at startup.

It's a 40 dollar part. If it fixes your brakes great. If it does not, well you got a new check valve to go with your new brake booster. Should be the last time you look at either of them.

 

[JBurt]

That's a good idea. Thanks.

 

[JBurt]

I used the check valve from my father in laws taco and had the same problem. Got the new booster from [MENTION=78895]DeathCougar[/MENTION], which was easy to install and worked like a charm. His used booster with a working check valve was the same price as a new check valve. Hard to beat.

Just make sure you get the gaskets before hand. The one between the booster and the master cylinder is paper and brakes easily when removing the master.

 

[AzCosta]

Had a similar problem as JBurt with intermittent booster problem. Did all the tests, check valves, bleed brakes, vacuum test. What I finally found was a hissing noise that occurred inside the cabin at the brake pedal area. Only happened when I pushed the pedal down 1/2" or so and the hiss was continuous. (advise.. turn off radio and AC fans so you can hear). Push down further or let off entirely on the pedal and it went away. Was literally depleting all of the vacuum built up in the booster in seconds by pushing the brake pedal 1/2". Hard braking occurred at any speed and only immediately following when I road the brake pedal or feathered it. Very noticeable backing out of an inclined driveway! Yikes. Remanufactured booster from O'reilly and I am back in business. Took 2.5 hrs to replace.

 

[AvatarT4R]

I used the check valve from my father in laws taco and had the same problem. Got the new booster from [MENTION=78895]DeathCougar[/MENTION], which was easy to install and worked like a charm. His used booster with a working check valve was the same price as a new check valve. Hard to beat.

Just make sure you get the gaskets before hand. The one between the booster and the master cylinder is paper and brakes easily when removing the master.

Just quoted a new check valve from my local dealership, for $58.00, so you must have gotten one hell of a deal!:becky:

 

[Dezert4Runner]

Just quoted a new check valve from my local dealership, for $58.00, so you must have gotten one hell of a deal!:becky:

I bought and replaced my brake booster with a junkyard one last weekend and paid $50. It’s not uncommon to find them for $50 +/- used. Car-part.com will show local listings but not always prices. Good resource to use for salvage yard inventory.

Also, the check valve can be had from a Toyota dealership for far less than $58. Most of the dealerships are generally above list price, so shop around online unless you’re in a bind for one same day.

Valve Assembly Vacuum C - Toyota (44730-60060) | Toyota Parts

 

[AZBub]

Just quoted a new check valve from my local dealership, for $58.00, so you must have gotten one hell of a deal!:becky:

well, in 2015 it was probably cheaper. Look when he last posted.


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