Combination of flanged axles and solid mounted calipers.Question for you guys. When im going through a whoop section then go to flat, i have to pump the brakes. Driving on street is fine but sometimes if the truck idles for a bit in drive then go to drive it gets soft again. I have wilwoods on all 4 corners, not leaking any fluid (anymore), and running stock master/ booster. It was suggested to me by a friend that i need to run a wilwood master cylinder. Is it a pressure issue due to having a total of 16 pistons stopping the truck?
This is all from todays experience in barstow. Oyherwise the truck did really good.
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Would having a portioning valve help with this; that i have.Combination of flanged axles and solid mounted calipers.
The axle flange flexes and pushes the caliper piston away from the rotor.
You can try a 2lb residual valve on the rear brake line to keep some pressure in the line.
Between the floor and stationary id say the pedal travels half way before i can lock them up if i need to. I almost thought it was a vacuum issue because of when i have to pump them. For example, I didn’t lose them in the whoops but when i was driving or coasting on pavement. It did it again when i was coasting down a hill and had to “build pressure” with a couple pumps. Then another time in a parking lot it went soft and had to pump. So it feels like to me its only happening under coasting and not under power, if that makes sense.Do you have a lot of pedal travel to lock up the brakes even when the brakes work correctly?
If the master is too small, the brakes will work very easily but requires far more pedal travel. It also means (like do dah said) that when you have axle flex and solid calipers, it requires even more pedal travel to now fill and tighten up the pads before braking starts as the rotor pushed the pistons back in a bit.
You need a larger master but the residual valves might help mitigate the issue for now.