Mushy Brakes at Low Speeds

[RaptorSentry]

I am having mushy brakes when driving at low speeds (less than 20 mph). At high speeds brakes the brakes are nice and solid and work great all the way down to a stop. Any ideas what is wrong or anything I can troubleshoot? Just a guess would be low vacuum pressure at low speeds.

[70cst]

ttt

[Rod Run]

Sounds like a vacuum issue.

Do you have a radical cam, or no canister, or maybe a vacuum leak?

[Texasredneck69-C10]

I would bet you have a vacuum leak or just poor vacuum suction. I you find a leak its an easy fix, if you don't have a leak. you can buy an electric vacuum pump that will fix your issues but they are expensive. Hope that helps.

[Rod Run]

Originally Posted by Texasredneck69-C10

I would bet you have a vacuum leak or just poor vacuum suction. I you find a leak its an easy fix, if you don't have a leak. you can buy an electric vacuum pump that will fix your issues but they are expensive. Hope that helps.

Or you buy a vacuum canister because those are cheap. The big Block in my Camaro produces next to nothing for vacuum, so I had to go with a canister and it really helped

[RaptorSentry]

Thanks for the help, looks like I'll be trouble shooting this weekend looking for the leak.

[davepl]

Normally your vacuum canister should hold enough vacuum for one or two brake applications such that you wouldn't notice the lower vacuum available at idle/low speed. But if the reservoir part has failed, you'll notice it. Check to see if it holds vacuum for a minute or two after shutting off the truck.

If its not a vacuum advance issue, have you touched the brakes? Could be air in the lines, because low vacuum usually is described as a harder pedal, or taking more force.