98 k1500 Pedal wont get fully hard?

[ChrisR36]

I bought this K1500 roughly a year ago, its a 98 scsb 4x4 and did all around brakes when I first got it. The pedal never got "fully" hard but was drive able. I brought it to a shop, they put a new master cylinder in it about a month ago because mine was leaky, and still no change. There is no brake fluid leaks, all the lines look great (Tennessee truck, so very little rust). When they bleed my brakes at the shop they said they bleed the crap out of them and there was still a little play in the pedal. Im stuck here at a dead end, when I bleed the brakes this summer to try to figure this out, I noticed a little fluid would come out around the wheel cylinder bleeder valve as well, Im thinking ive got bad ones, but is there any way to be certain. The truck stops like it should once you get passed the play. Could it be a bad pedal assembly?

 

[magnumb]

Please note these trucks are known for soft pedals as the brake calipers used in most 1500s come with low drag calipers. When the brake pedal is released it pulls the brake pad away from rotor slightly. When you apply the brakes it needs to make-up that distance and that is mostly what you are feeling. Does it continue to sink almost to floor with hard pressure? and does the pedal return to acceptable height after it's released? The pedal should be soft for maybe an inch then get firm but not hard like a modern car/sports car.

There could be air trapped in the ABS system and you need a special scan tool to activate this while bleeding.
I would change out rubber lines to stainless or get new rubber as these swell after awhile and then have someone activate abs while bleeding. Also adjust rear drums.
Alot of people think these trucks have horrible brakes...but looking the stop distance numbers says otherwise. It's mostly the feel that's not the best due to low drag calipers.

 

[BubbaGump]

I hate it when it won't get hard...

 

[jsfrmsj]

Had the exact same problem, turned out to be a very tiny leak from the rear brake bleeder screw. As stated above you need a scan tool to properly bleed the system and adjusting the rear drums helps a lot as well.

 

[east302]

Im stuck here at a dead end, when I bleed the brakes this summer to try to figure this out, I noticed a little fluid would come out around the wheel cylinder bleeder valve as well, Im thinking ive got bad ones, but is there any way to be certain.

You may have unscrewed the bleeder too much, but if it leaks with just the slightest opening of the bleeder, then I'd probably replace the bleeder and follow up with a new wheel cylinder if that doesn't work.

With the bleeders screwed in, they don't leak, do they?

Immediately after the automated ABS bleed, follow up with a regular bleed at all four corners.

Proper drum adjustment is key, too.



Sent from my iPhone using Tapatalk

 

[ChrisR36]

Please note these trucks are known for soft pedals as the brake calipers used in most 1500s come with low drag calipers. When the brake pedal is released it pulls the brake pad away from rotor slightly. When you apply the brakes it needs to make-up that distance and that is mostly what you are feeling. Does it continue to sink almost to floor with hard pressure? and does the pedal return to acceptable height after it's released? The pedal should be soft for maybe an inch then get firm but not hard like a modern car/sports car.

There could be air trapped in the ABS system and you need a special scan tool to activate this while bleeding.
I would change out rubber lines to stainless or get new rubber as these swell after awhile and then have someone activate abs while bleeding. Also adjust rear drums.
Alot of people think these trucks have horrible brakes...but looking the stop distance numbers says otherwise. It's mostly the feel that's not the best due to low drag calipers.

initially, when me and my uncle did the brakes, he had a scan tool and bleed them. But if I replace the master cylinders now, will I need to bleed it again with the scan tool? The pedal doesn't go to the floor, and it raises all the way back to the top after I hit them. The truck does have some damn good brakes, and ohh ive tested them many times lol.

 

[ChrisR36]

You may have unscrewed the bleeder too much, but if it leaks with just the slightest opening of the bleeder, then I'd probably replace the bleeder and follow up with a new wheel cylinder if that doesn't work.

With the bleeders screwed in, they don't leak, do they?

Immediately after the automated ABS bleed, follow up with a regular bleed at all four corners.

Proper drum adjustment is key, too.



Sent from my iPhone using Tapatalk

I can unscrew the bleeder about 1/4 of a turn before I start to get fluid out of the bleeder and around it. The moment the fluid comes out of the bleeder, its comes around it aswell. So I cannot get fluid out of the bleeder without getting it around the screw.