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Combinations
Samba Member
Joined: March 19, 2010
Posts: 286
Location: Massachussets
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 Posted: Wed Oct 07, 2015 3:52 pm Post subject: Brake could work better |
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Hi everyone, i redid the entire brake system on my 76 bay except the big vacuum system in front of the master cylinder. Otherwise everything is new.
On the rear wheels I opened the brake shoe so that so wheel turn just enough.
But when I drive and brake the result is really not there. Even if I pump, It's just not braking enough.
Any idea? |
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SGKent 
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Joined: October 30, 2007
Posts: 41031
Location: Citrus Heights CA (Near Sacramento)
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| Posted: Wed Oct 07, 2015 3:58 pm Post subject: |
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how did you bleed the brakes?
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1967250s
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Joined: May 02, 2007
Posts: 2137
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| Posted: Wed Oct 07, 2015 4:01 pm Post subject: |
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It is called a "brake" system, not "break". It sounds like the booster is either; not getting vacuum, or is shot. Take off the vac line and see if there is vacuum. Could be the one way valve is just in backwards.
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aeromech
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Joined: January 24, 2006
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Location: San Diego, California
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| Posted: Wed Oct 07, 2015 4:08 pm Post subject: |
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I agree. Troubleshoot the booster
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Combinations
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Joined: March 19, 2010
Posts: 286
Location: Massachussets
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| Posted: Wed Oct 07, 2015 4:32 pm Post subject: |
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| 1967250s wrote: |
| It is called a "brake" system, not "break". |
You are right! Thanks for pointing that.
It has been bleed with a pressure pump form a mechanic.
Can the booster be fixed, or is it a sealed part that you need to replace totally? I see that aftermarkets goes around $150. Any experience with that? |
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aeromech
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Joined: January 24, 2006
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Location: San Diego, California
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| Posted: Wed Oct 07, 2015 5:12 pm Post subject: |
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Best to have yours rebuilt. Lots of cars use boosters and there are places throughout the country that rebuild them. Just do a search for your area.
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Lead Mechanic: San Diego Air and Space Museum
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Combinations
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Joined: March 19, 2010
Posts: 286
Location: Massachussets
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| Posted: Wed Oct 07, 2015 5:39 pm Post subject: |
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| I will look at rebuilds, I will also check all the entire line that goes to the engine. |
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Tcash
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Joined: July 20, 2011
Posts: 12844
Location: San Jose, California, USA
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| Posted: Wed Oct 07, 2015 6:02 pm Post subject: |
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Did you open both shoes or just one?
You may need to loosen the E-Brake cables and re-adjust.
Then adjust your E-Brake.
Good Luck
Tcash |
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Combinations
Samba Member
Joined: March 19, 2010
Posts: 286
Location: Massachussets
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| Posted: Wed Oct 07, 2015 6:04 pm Post subject: |
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| Tcash wrote: |
Did you open both shoes or just one?
You may need to loosen the E-Brake cables and re-adjust.
Then adjust your E-Brake.
Good Luck
Tcash |
Yes both shoes in the back. with e brake not on. I have disk brake in the front. |
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busdaddy
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| Posted: Wed Oct 07, 2015 6:33 pm Post subject: |
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But did you physically unbolt the E brake cables at the front so they were loose?, and when you adjusted did you tighten each star equal clicks until it wouldn't turn any more (long past when the wheel locks) and then back them off equal clicks until the wheel just spun? (then adjust the brake cables). This assumes you removed both drums and pushed the shoes side to side to confirm none of the pistons were stuck and inspected the shoes for lining thickness as well as heat checking and separation.
How about the calipers, did you confirm all 4 pistons move freely and the notches were oriented per your Bentley manual?, when you reinstalled the shims did you use much antisqueal goo on them? did the notches line up with the piston cutouts?
Did you flush the system and make sure all 5 bleeders ran clear? (don't forget the proportioning valve).
Have you ever changed the flexible hoses or at least know how old they are?
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FlatfourFrenchy
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Joined: March 13, 2013
Posts: 297
Location: Boonville, MO
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| Posted: Wed Oct 07, 2015 6:36 pm Post subject: |
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Disc brakes will also need to be "burnished" with a good dose of heat before they have all of their stopping power. I will never let anyone but myself drive a vehicle that I just put brake pads on . Not until I burnish them in by stopping really hard without skidding a few times and then they will work properly. Along with all other properly adjusted components.
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Wildthings
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| Posted: Wed Oct 07, 2015 8:19 pm Post subject: |
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| If the booster was working correctly before you did the brake work, it should still be working correctly once the work was done. I would suspect that the brakes were not bled properly or the rears are badly out of adjustment. |
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Combinations
Samba Member
Joined: March 19, 2010
Posts: 286
Location: Massachussets
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| Posted: Thu Oct 08, 2015 6:48 am Post subject: |
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| busdaddy wrote: |
But did you physically unbolt the E brake cables at the front so they were loose?, No, I will do that and when you adjusted did you tighten each star equal clicks until it wouldn't turn any more (long past when the wheel locks) YES and then back them off equal clicks until the wheel just spun? (then adjust the brake cables). This assumes you removed both drums and pushed the shoes side to side to confirm none of the pistons were stuck YES and inspected the shoes for lining thickness as well as heat checking and separation. I don't know about the heat checking, what is it?
How about the calipers, did you confirm all 4 pistons move freely and the notches were oriented per your Bentley manual?, YES when you reinstalled the shims did you use much antisqueal goo on them? did the notches line up with the piston cutouts? YES
Did you flush the system and make sure all 5 bleeders ran clear? YES(don't forget the proportioning valve).
Have you ever changed the flexible hoses or at least know how old they are? |
[/b] YES
Actually I changed first the master cylinder because it had a leak, so it could be that it leaked inside the booster. I will double check that. |
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