Brake Booster Question

[airemdwn]

I have an 89 Blazer that the wife drives, just for the street and winter. It is 100% stock and to me its feels great, however.

She doesnt like the brake pedal feel. It is " too hard to push". She insists it stops fine but she just "feels like i really have to push hard to get it to stop"
It feels linear to me and maybe it stiffens harder towards the end of travel than it should but its not scary and the pedal is otherise very good.
Could the booster be bad?

Of course in my obsessive make something harder than it has to be way i am thinking about seeing if i 3/4 ton burban booster would work and maybe offer more assist? Anyone ever try differnt boosters? No i am not doing hydroboost on my wifes blazer. Well not till i get it first.

 

[sweetk30]

hydro boost is a bit harder to push anyways over vac brakes but a lot better in my opinion.

older trucks tend to be harder to push than new fluffy vehicles these days .

and were in pa ? i am in horseheads ny near pa ny boarder.

 

[imiceman44]

A 3/4 ton or 1 ton booster will have more assist, you can try that, even a replacement might be better than the original booster.

I have an 89 Blazer that the wife drives, just for the street and winter. It is 100% stock and to me its feels great, however.

She doesnt like the brake pedal feel. It is " too hard to push". She insists it stops fine but she just "feels like i really have to push hard to get it to stop"
It feels linear to me and maybe it stiffens harder towards the end of travel than it should but its not scary and the pedal is otherise very good.
Could the booster be bad?

Of course in my obsessive make something harder than it has to be way i am thinking about seeing if i 3/4 ton burban booster would work and maybe offer more assist? Anyone ever try differnt boosters? No i am not doing hydroboost on my wifes blazer. Well not till i get it first.

 

[Fordum]

I don't know years of Blazers, so this is a guess. But, assuming you have disk front and drum rear, get under and adjust the rear.
If the self adjusters are not working, and they often don't, then it will make it seem harder to stop.
Thats a quick and easy fix. Next, if that does not fix it, park the truck, switch it off and wait a couple of minutes.
Then, with it off, press and release the brake pedal. You should get at least a couple of fairly easy pushes before the vacuum runs out.
If you don't, then you either have a vacuum input problem or a leak in the booster or check valve.

Once you run out of vacuum, press and hold the pedal down hard, and crank the truck. You should feel a pretty good drop in the pedal when it cranks up.

If all that shows good, but the pedal is still not soft enough, you could swap the booster you have for a dual chamber one to get more boost.

If its an automatic, make sure your idle speed is not too high. That will also make it harder to stop.

 

[airemdwn]

Thanks,
I have changed all the brakes and fluids and fixed all the major leaks and goofy fixes they did. It looked to have lots of brake things done to it before i bought it. One line on the rear axle was replaced and there was a compression fitting on the other side and near the master so im guessing the MC was leaking and maybe dried out the booster inside, maybe thats part of the problem. Mostly typical new to me vehicle maintenance stuff but ill look at the booster. i did drive it more and panic/ really hard stops ( which my wife never does) it does seem.... off, almost like there is no assist.
Im near Allentown and hopng to be ready to take a trip to Rausch before the year is out.

 

[496truck]

The vacuum booster is shot. Fairly common problem on these trucks. Prob started out with a whooooosh sound every time the brakes were pressed. Now it's just a hard pedal.

Mine got to a point where I could step on the brakes and they worked fine. But if I let off and had to get right back on them the pedal was hard as a rock and difficult to stop the truck. That's when I replaced it. No more whooosh, no more funny idle, and brakes that work. Stock replacement 1/2 ton booster would be fine.

 

[diesel4me]

The booster doesn't have any fluid going thru it,so no way could it have "dried up",if its a vacuum booster--hydroboost does though,and a powwer steering pump getting weak will cause a hard pedal,as it powers both the brakes and steering..--more likely ,if its vacuum assist,the diaphram is torn a little and wont allow full assist ,it also will affect engine performance if the vacuum loss is enough,like a poor idle when the brake is applied.......Another possibility is you may have wheel cylinders or calipers that are getting seized in their bores,that will make for a hard pedal,with not much actual "braking" taking place....a crimped steel line or flex hose thats failing internally can also cause this...I have had to replace several vacuum boosters on my old GM's,the canister on them rusts thru near the bottom often,or the diagphram gets brittle and tears and you lose power assist...usually you'll hear a hissing noise under the dash when applying the brakes or holding the pedal down,and you'll hear the idle quality affected--or you may hear hissing coming from beteween the booster and master cylinder under the hood with the engine idling,depending on what side the diagphram failed on...

 

[496truck]

He was saying if the master cyl leaked into the booster (at one time) and the fluid affected the seals in the booster.