brake issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**bigmac73** · 07-08-2014, 02:49 PM

about two weeks ago i had the a new MC installed, wheel cylinders and new drum installed on the rear, when i picked up the truck the brake pedal felt great, plenty of pedal did not have to pump them, would stop on a dime , now after driving it i am back to the old routine of pumping them a few times to get a good stop and it seems like i lost a little pedal as well,

should i try to adjust the rear out a little? or take it back to the shop to get them to check it out

FYI- manual brakes, front calipers, rotors and hoses where replaced a year ago

ssxty8 · 07-08-2014, 04:11 PM

IMHO, take it back to the shop. Maybe a left-in air bubble moved to the wrong place and is effecting your pedal feel. They should also verify the rear shoes adjustment for you. A couple years ago, I had a 70 Nova with manual drums all around, and the pedal feel and action was one of the best I've ever felt, so yours should be the same or better with front discs. IMO pedal pumping shouldn't be necessary. Two weeks is too short of a warranty.

Lattimer · 07-08-2014, 04:18 PM

Pumping usually means you have air in the system

**Stocker** · 07-08-2014, 05:36 PM

Quote:

Originally Posted by Lattimer

Pumping usually means you have air in the system

Yup. Regardless, you paid them for the job and it's not right. Give 'em a chance to make it right. If you tear into it yourself, any liability on their part will go out the window.

70SBC10BOB · 07-09-2014, 12:54 AM

I have seen this situation many times when the master cylinder has been replaced. For some unknown reason, some tech refuse to bench bleed the new master. If you don't bench bleed the master, it leaves an internal air bubble that effects the system eventually.

When the air bubble has moved out of the master and into the lines, it causes the low/spongy pedal. Have them re-bleed the system and re-adjust the rear brakes. (Rear brake adjustment effects the brake pedal height and performance.)

Only other concern, was it a new master or rebuilt. Rebuilt masters are never my first choice. It is the heart of your brakes. You don't want to save $25 bucks on a rebuilt master, only wreck the truck when it fails.

Good luck.

07-08-2014, 02:49 PM	#1
bigmac73 Senior Member Join Date: Mar 2012 Location: Chesapeake, Va Posts: 1,275	brake issues about two weeks ago i had the a new MC installed, wheel cylinders and new drum installed on the rear, when i picked up the truck the brake pedal felt great, plenty of pedal did not have to pump them, would stop on a dime , now after driving it i am back to the old routine of pumping them a few times to get a good stop and it seems like i lost a little pedal as well, should i try to adjust the rear out a little? or take it back to the shop to get them to check it out FYI- manual brakes, front calipers, rotors and hoses where replaced a year ago __________________ Mike 72 C-10 Cheyenne off frame resto and Upgraded to 4 wheel disk, Tilt, Dakota Digital Dash / Rear slider. 421 SBC / TH350 3000RPM Stall Progression Ignition /Holley 750 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks

07-08-2014, 04:11 PM	#2
ssxty8 Registered User Join Date: Apr 2014 Location: PR Posts: 85	Re: brake issues IMHO, take it back to the shop. Maybe a left-in air bubble moved to the wrong place and is effecting your pedal feel. They should also verify the rear shoes adjustment for you. A couple years ago, I had a 70 Nova with manual drums all around, and the pedal feel and action was one of the best I've ever felt, so yours should be the same or better with front discs. IMO pedal pumping shouldn't be necessary. Two weeks is too short of a warranty.

07-08-2014, 04:18 PM	#3
Lattimer Registered User Join Date: Jan 2013 Location: Mickleton, NJ Posts: 1,776	Re: brake issues Pumping usually means you have air in the system __________________ Shawn 1970 Chevy C-10 SWB, 350, TKO 600 5 speed My build http://67-72chevytrucks.com/vboard/s...d.php?t=559881

07-09-2014, 12:54 AM	#5
70SBC10BOB Registered User Join Date: Jan 2014 Location: Murrieta, CA Posts: 41	Re: brake issues I have seen this situation many times when the master cylinder has been replaced. For some unknown reason, some tech refuse to bench bleed the new master. If you don't bench bleed the master, it leaves an internal air bubble that effects the system eventually. When the air bubble has moved out of the master and into the lines, it causes the low/spongy pedal. Have them re-bleed the system and re-adjust the rear brakes. (Rear brake adjustment effects the brake pedal height and performance.) Only other concern, was it a new master or rebuilt. Rebuilt masters are never my first choice. It is the heart of your brakes. You don't want to save $25 bucks on a rebuilt master, only wreck the truck when it fails. Good luck. __________________ 1970 C 10 A work in progress!!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.