question for you dieselers out there.

[SunlitComet]

question for you dieselers out there. or those with a hydroboost conversion.....

admit it. you have a hydroboost brake booster system. i know it. you know it. no point in denying it. when you are say driving at a good speed and you apply the brakes how much initial travel of pedal do you have from foot on the pedal to actual braking force kicking in?

any other peculiar things you noticed compared to a vacuum booster like say how easy it is to depress pedal.

 

[arveetek]

I'd say there is probably 1.5" to 2" of movement of brake pedal before brakes engage. I'll have to look more closely and get back to you.

Brake assist feels about the same as vacuum; not much difference as far as pedal pressure required.

One little quirk I've noticed is that when I'm applying brakes while going around a curve, as soon as I let off brake pedal, power steering assist is suddenly increased due to less draw on the system from the power brakes, so the steering wheel suddenly responds easier and can cause you to jerk the wheel a bit. Not bad at all, just something I can feel.

I have about three full applications of the pedal when the engine is off before the stored pressure in the system bleeds off and I lose all power assist. Once that's done, wow! Talk about needing to use both legs to stop! Much harder to overcome than a vacuum assist system.

Casey

 

[SunlitComet]

The more info the better. Can I assume you have not made any performance mods or upgrades to your brake system system such as rotors, pads and what not? Also do have have the vertical cooler for the power fluid on the left in front of your condensor?

---------- Post added at 09:33 AM ---------- Previous post was at 09:20 AM ----------

My plan is to mate the hydroboost system with a nbs master cylinder but the booster bore will need to be machined to open it up so it will fit. I am also looking into possibly machine a pushrod extension in it to reduce the application delay. I believe the big delay in brake application on our OBS platform is because the booster pushed is to short and by the time it contacts the plunger and gets past closing the reservoir ports off the pedal has traveled about 3-4 inches. And in a vacuum booster system it will only let you move it so fast when you slam on it and that is a long reaction time I would like to eliminate.

 

[arveetek]

Yes, stock braking system. Yes, I have the aux. cooler for the hydroboost system.

I measured the brake pedal movement last night, and here's how I measured: I applied the brake pedal just enough to keep the truck from moving with the engine running and the tranny in drive (engine at normal operating temp and low idle). It took 2.5" of brake pedal application to keep the truck from moving. When driving normally, I can feel the brakes just start to drag after about 2" of application.

Casey

 

[SunlitComet]

Sweet, the upgrade will definitely change things for the better for me then.