| Vacuum Brake Boosters Needed [message #371543] |
Mon, 27 November 2023 20:55  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Senior Member |
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Recently I have been experiencing a braking petal feel issue on my MH. My braking system is 80mm calipers up front, Lenzi big brakes center axle, drum brakes rear axle, metric sensitized booster, a GMC combination valve (the correct one) and 3 different MC's that I've tried with the same feel. When I hit the brakes quick and hard as if in a sudden emergency, there is about a 1second delay before I have actual brakes. When I hit the brakes hard I can hear an air or hydraulic hiss for that 1 second and then have brakes. Tried 3 different MC's with the same delay. OEM 1 1/4" MC, step bore 40mm to 1 1/4" MC, and a 37mm MC from a 2005 Chevy Suburban. The last one brought the pedal to the top of travel so the delay is maybe a 1/2second. So, I finally wrote a note to Dave L to ask him if something could be happening inside the booster. He called me and reported that several others had experienced the same issue and the common thread seems to be the Metric Booster. While he does not have a explanation for the delay, it is pretty clear that the metric booster is failing internally somehow. He has had others replace the booster with a sensitized OEM booster. It solved the issue. Dave has been rebuilding vacuum brake boosters for several years now, but had to stop doing it because he cannot get people who bought his rebuilt booster to return the core to him. He no longer has cores. Does anyone here have a source for OEM boosters? If we are to continue to have boosters for our coaches we need to come together and find a source. If you have one in your garage or on your parts coach that you can let go, please contact Dave and work something out.
So now, I am in now in need of an OEM booster. If you have one that you can spare, please contact me.
TIA
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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| Re: Vacuum Brake Boosters Needed [message #371547 is a reply to message #371545] |
Thu, 30 November 2023 13:22  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Senior Member |
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RF_Burns wrote on Tue, 28 November 2023 06:29Larry,
Would this mean you could no longer use the stepped Master Cylinder (MC) because the stepped MC is metric and the OEM booster is not? Or has a stepped MC been found that fits our OEM booster?
I have a relatively new OEM sensitized booster installed from DaveL and I would like to try the stepped MC.
For those of us that need the metric booster for the stepped MC, Dave is sensitizing the OEM booster and assembling it with a Metric cover. OEM internals with a Metric look. Interesting to me that the Metric cover fits. With the metric cover, you can use the OEM MC or any of the MC's that require a Metric Cover. I've had the OEM MC, the Step MC, the P30 MC and the 37mm MC on my metric booster. With the metric booster you have to make some changes to the MC brace. Just bend it a little in some places to clear the top of the booster and elongate the top mounting holes so the bolts fit through into the threaded top holes.. JWID
Larry
78 Royale w/500 Caddy
Menomonie, WI.
[Updated on: Thu, 30 November 2023 13:23] Report message to a moderator |
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