When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hey All,
I converted my manual brake '73 to hydroboost power brakes. The power steering pump was fine before the conversion, but now it wines constantly. The power steering works well, and the brakes are awesome. The noise is especially loud when I press on the brakes or turn the steering wheel. I've been told that there is air in the system and I just have to drive it to get it all out. I'm at the point where I just want to remove the hydroboost system and go to a vacuum booster. The problem is that I have a big block with roller rockers and slightly higher rocker covers.
Is there a vacuum booster that has a smaller outside diameter with dual diaphragms that will fit my application? My master cylinder is a Wilwood unit.
P/S pump "whine" usually occurs with insufficient level of fluid in the reservoir. But it can also indicate some significant internal wear/damage in the pump.
If your fluid did get low and start the whine, and then you topped it off, it might still whine because of air in the system. To get rid of it, raise the front wheels, start the engine and turn steering wheel lock-to-lock right then left several times at moderate pace. If it stops whining, you had air in the system. If it doesn't, your pump or the control valve might have other issues.
Stock diameter brake booster should fit fine and will provide better performance than a small booster.
How tall are your valve covers? I have Ansen valve covers and roller rockers. Only issue is having to use a wobble socket to get to the valve cover bolt above #7. Not a big deal.
The power brake booster/valve cover interference requiring the notch was a C2 issue. C3s have more room.
Might want to check out this thread from 2017. A forum user 69427, who is very knowledgeable, relates how he is using an 84 booster (smaller diameter and half the weight) with a C5 master in his C3. Could be an option if you really want to go that route.
If you keep the stock diameter brake booster there are several tall style valve covers that will fit with the oem diameter booster.
I purchased a set of Teague Custom Marine tall valve covers that are designed to fit with an overhead marine exhaust system for a big block Chevy.
I also purchased a set of new Ansen's for a big block.
Both have clearance for the oem diameter booster and give clearance for roller rockers.
Last edited by OldCarBum; Nov 30, 2021 at 05:03 PM.
Also there is a company called CFR Performance that has 1/2" taller stock looking valve covers with the power booster indentation. I use these on my big block with the stock size booster with no problems.
Those are nice, but regardless it is tight in there. I am going to look into the C4 swap. I even considered swapping over to manual brakes to make it easier to get to the spark plugs. I am ditching the factory A/C and going with Vintage Air for that very reason.
Small Diameter Brake Booster?
