Power Brakes... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Striker169 · 11-24-2005, 10:48 PM

Ok so I added power brakes to the truck a while back, and I just finally tonight got the brakes all adjusted and whatnot (I think)

Well two questions first when I brake it doesn’t even come close to locking up and it doesn’t stop all that fast either. I replaced everything on the brake system except the lines and prop valve. I have thoroughly bled the system. Checked all the hardware in the brakes everything works. Do you think that because I have a 454 and the prop/master cylinder is made for a 350 C10 that could be it? Would I be better off with like a C20 prop and mc?

Also when I hit the brakes my engine seems to idle odd, do you think that my cam is too aggressive for the power brakes?

Sweet72 · 11-24-2005, 11:24 PM

Sounds like your vacuum booster has a leak as you shouldn't notice a difference in idle unless you have a vacuum leak. Also, if you've changed out to a disc/drum setup, I believe the prop valve is different in a drum/drum versus disc/drum setup. Did you install a new vac booster or old setup from another truck? I've gone through 2 old boosters on my GMC since the power brake swap, and believe me, power brakes with a blown booster diaphram is harder to stop than manual brakes. It doesn't matter if you swapped the power brake setup from a small block to big block. Good luck!

Longhorn Man · 11-24-2005, 11:24 PM

what are your cam specs?
There is no P/N differance for big block trucks verses small block trucks.

**truckdude239** · 11-24-2005, 11:26 PM

umm soundds like an bad power booster

Striker169 · 11-25-2005, 02:45 AM

dam, I paid $100 for the power brake mc and prop valve. But I guess that is what it is. Is there anyway to fix it other than getting a new brake booster?

Sweet72 · 11-25-2005, 09:08 AM

To my knowledge there are no repair parts available for retail sales. New boosters $200+. The guy in the link below says he'll rebuild and replate for 145 postage paid. Good deal if your into show quality correct parts.

Check out this link...
http://www.brakeboosters.com/

**truckdude239** · 11-25-2005, 09:14 AM

http://www.partsamerica.com/ProductD...pe=250&ptset=A

89.88 reman 30 dollar core returnable to any Advance Auto, Checker, Schuck's, or Kragen store with lifetime free replacement

theres an 10 dollar difference between the other bake booster they have because it has no mc on it and it sells for 79.88 for 10 buxs i'd get the one with new mc

best part is free shiping on all parts over 50 buxs

just my $.02

Sweet72 · 11-25-2005, 07:33 PM

That's one heck of a price there truckdude. I'd have to question the quality of those parts, but with a warranty like that you can't lose for a driver!

**truckdude239** · 11-25-2005, 08:20 PM

i get all my parts from advance auto or parts america if it ever goes bad i just take it back but so far i've never had any trouble with the reman parts beats paying 200 buxs for an new one i get reman alt. and water pumps with life time free replace ment never any problems

11-24-2005, 10:48 PM	#1
Striker169 Car O'Holic Join Date: Jan 2005 Location: Austin, Tx. Posts: 692	Power Brakes... Ok so I added power brakes to the truck a while back, and I just finally tonight got the brakes all adjusted and whatnot (I think) Well two questions first when I brake it doesn’t even come close to locking up and it doesn’t stop all that fast either. I replaced everything on the brake system except the lines and prop valve. I have thoroughly bled the system. Checked all the hardware in the brakes everything works. Do you think that because I have a 454 and the prop/master cylinder is made for a 350 C10 that could be it? Would I be better off with like a C20 prop and mc? Also when I hit the brakes my engine seems to idle odd, do you think that my cam is too aggressive for the power brakes? Last edited by Striker169; 11-24-2005 at 10:52 PM.

11-24-2005, 11:24 PM	#2
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Power Brakes... Sounds like your vacuum booster has a leak as you shouldn't notice a difference in idle unless you have a vacuum leak. Also, if you've changed out to a disc/drum setup, I believe the prop valve is different in a drum/drum versus disc/drum setup. Did you install a new vac booster or old setup from another truck? I've gone through 2 old boosters on my GMC since the power brake swap, and believe me, power brakes with a blown booster diaphram is harder to stop than manual brakes. It doesn't matter if you swapped the power brake setup from a small block to big block. Good luck! __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction. Last edited by Sweet72; 11-24-2005 at 11:31 PM.

11-24-2005, 11:24 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Power Brakes... what are your cam specs? There is no P/N differance for big block trucks verses small block trucks.

11-24-2005, 11:26 PM	#4
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Power Brakes... umm soundds like an bad power booster __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

11-25-2005, 02:45 AM	#5
Striker169 Car O'Holic Join Date: Jan 2005 Location: Austin, Tx. Posts: 692	Re: Power Brakes... dam, I paid $100 for the power brake mc and prop valve. But I guess that is what it is. Is there anyway to fix it other than getting a new brake booster?

11-25-2005, 09:08 AM	#6
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Power Brakes... To my knowledge there are no repair parts available for retail sales. New boosters $200+. The guy in the link below says he'll rebuild and replate for 145 postage paid. Good deal if your into show quality correct parts. Check out this link... http://www.brakeboosters.com/ __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

11-25-2005, 09:14 AM	#7
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Power Brakes... http://www.partsamerica.com/ProductD...pe=250&ptset=A 89.88 reman 30 dollar core returnable to any Advance Auto, Checker, Schuck's, or Kragen store with lifetime free replacement theres an 10 dollar difference between the other bake booster they have because it has no mc on it and it sells for 79.88 for 10 buxs i'd get the one with new mc best part is free shiping on all parts over 50 buxs just my $.02 __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube Last edited by truckdude239; 11-25-2005 at 09:17 AM.

11-25-2005, 07:33 PM	#8
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Power Brakes... That's one heck of a price there truckdude. I'd have to question the quality of those parts, but with a warranty like that you can't lose for a driver! __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

11-25-2005, 08:20 PM	#9
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Power Brakes... i get all my parts from advance auto or parts america if it ever goes bad i just take it back but so far i've never had any trouble with the reman parts beats paying 200 buxs for an new one i get reman alt. and water pumps with life time free replace ment never any problems __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube



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