Brake pedal slow return after new booster...

MatSLO

I'm Awesome
Joined
Jan 15, 2018
Messages
100
Reaction score
29
Location
Slovenia, Europe
Recently, I noticed my brake booster failing. Whooshing sound when applying brakes, hard pedal, a couple of times the engine died while idling/slow moving etc.

I ordered a new brake booster (SKP SKBB005, the cheapest option on rockauto.com) and had it installed by my mechanic.
Now I'm noticing that the brake pedal is slow to return after braking. I actually feel that the brakes do not release immediately after I let go of the pedal. It's annoying and I worry this might not be safe.
Has anybody experience this? Is the new brake booster of bad quality or might there be another problem?
 

Hipster

I'm Awesome
Joined
Mar 7, 2017
Messages
1,297
Reaction score
1,520
Location
Liberty, NC
Remanufactured part? I've had issues with aftermarket/reman boosters on several different vehicles.
 

Erik the Awful

Supporting Member
Supporting Member
Joined
Aug 9, 2019
Messages
2,415
Reaction score
4,009
Location
Choctaw, OK
I would suspect a bad brake hose. Is the pedal return spring still in place?
 

MatSLO

I'm Awesome
Joined
Jan 15, 2018
Messages
100
Reaction score
29
Location
Slovenia, Europe
I would suspect a bad brake hose. Is the pedal return spring still in place?

No idea. The work was done by my mechenic, not me. Is there a spring in the pedal? I didn't know that, where should I look (I apologize if this is a stupid question, I have limited knowledge about mechanical stuff)
 

Schurkey

I'm Awesome
Joined
Jan 14, 2018
Messages
3,952
Reaction score
3,496
Location
The Seasonally Frozen Wastelands
Recently, I noticed my brake booster failing. Whooshing sound when applying brakes, hard pedal, a couple of times the engine died while idling/slow moving etc.

I ordered a new brake booster (SKP SKBB005, the cheapest option on rockauto.com) and had it installed by my mechanic.
Now I'm noticing that the brake pedal is slow to return after braking. I actually feel that the brakes do not release immediately after I let go of the pedal. It's annoying and I worry this might not be safe.
Has anybody experience this? Is the new brake booster of bad quality or might there be another problem?
Take it back to the guy who installed it, tell him what you told us.

This is not your problem. You paid real money for this to be HIS problem. Allow him to do his job. His job may involve telling you the booster is defective. You may end up paying him twice for this, because if this is a failed booster, it's not his fault, and his diagnosis and second replacement of the booster deserves compensation.

OTOH, maybe he somehow screwed-up the installation. In that case, he owes you a re-do on whatever he did wrong. Maybe he missed something else that failed (which should have shown up during the test drive.) but he doesn't owe you a re-do on whatever additional repairs are needed unless they're the direct result of his screwup.

P.S. Do you buy your steak and potatoes at the grocery store, then take them to the restaurant to get them cooked and served? Most shops won't accept customer-supplied parts due to the liability issues inherent in defective parts.
 
Last edited:

east302

I'm Awesome
Joined
Oct 4, 2013
Messages
2,845
Reaction score
2,164
Location
Jackson, MS
Recently, I noticed my brake booster failing. Whooshing sound when applying brakes, hard pedal, a couple of times the engine died while idling/slow moving etc.

I ordered a new brake booster (SKP SKBB005, the cheapest option on rockauto.com) and had it installed by my mechanic.
Now I'm noticing that the brake pedal is slow to return after braking. I actually feel that the brakes do not release immediately after I let go of the pedal. It's annoying and I worry this might not be safe.
Has anybody experience this? Is the new brake booster of bad quality or might there be another problem?
Did you get a resolution to this?

Same booster here, same symptom.
 

MatSLO

I'm Awesome
Joined
Jan 15, 2018
Messages
100
Reaction score
29
Location
Slovenia, Europe
I took the truck back to my mechanic and he said a new master cylinder was also needed (too bad I didn't order it with the brake booster already).

Now it's better but still not quite good - still slightly spongy feeling and the pedal still (sometimes) doesn't return very quickly (but better than before).
The mechanic said that after installing the new master cylinder, they had some trouble bleeding the brakes because the ABS unit may be bad. When (normal) braking, I can feel a slight pulsation.

Now the question - where the hell do I get a replacement ABS unit /module? I couldn't find it at Rockauto.com...
While researching this, I also came across this video - maybe it's worth a try...:
xc_hide_links_from_guests_guests_error_hide_media
 

Schurkey

I'm Awesome
Joined
Jan 14, 2018
Messages
3,952
Reaction score
3,496
Location
The Seasonally Frozen Wastelands
That video does not apply from '88-newer. The '88 to '91 C/K truck is rear-wheel antilock (RWAL) only; and it uses a totally different ABS unit compared to the video. The '92--'94 C/K truck got 4 wheel anti-lock, and '95--up C/K got a different 4-wheel antilock unit.

Official procedure for '92--'94, and '95--newer is attached. Both the "Recommended" and the "Alternate" bleeding method requires a scan tool to cycle the ABS unit multiple times. A GM dealership would use a Tech 1 or Tech 2 scan tool, but select other scan tools can also cycle the ABS unit.
 

Attachments

  • 1990s_GM_Light_Truck_Kelsey_Hayes_ABS_Brake_Bleeding_Procedure_Ref_Cards.pdf
    130.2 KB · Views: 2

east302

I'm Awesome
Joined
Oct 4, 2013
Messages
2,845
Reaction score
2,164
Location
Jackson, MS
I took the truck back to my mechanic and he said a new master cylinder was also needed (too bad I didn't order it with the brake booster already).

Now it's better but still not quite good - still slightly spongy feeling and the pedal still (sometimes) doesn't return very quickly (but better than before).
The mechanic said that after installing the new master cylinder, they had some trouble bleeding the brakes because the ABS unit may be bad. When (normal) braking, I can feel a slight pulsation.

Now the question - where the hell do I get a replacement ABS unit /module? I couldn't find it at Rockauto.com...
While researching this, I also came across this video - maybe it's worth a try...:
xc_hide_links_from_guests_guests_error_hide_media
Just to update my question, my issue was the SKP SKBB005 booster. I swapped it out with a salvage yard unit and the slow-return pedal issue is resolved.

The ABS component in the video is three parts - the Kelsey Hayes module on top, the modulator valve below and the combination valve that the brake lines connect to. The module is apparently not serviceable or available new/reman (for the 95-ish and up versions, at least). There was a thread on it a while back.
 
Top