More power from pumping brakes

[TDI Power]

Recently I noticed when standing at a red light and pump my brakes a few times, my car takes off much faster than if I didnt pump the brakes. It feels very peppy for 5 minutes or so, and the brake pedal is more sensitive too.

Anyone have any ideas what might be causing this?

 

[Toronto_Vento]

When was the last time you had your brake fluid flushed? Sounds to me like you have a bit of low pressure. Pumping the brake pedal increases the presure of the hydraulic fluid in the system. That means your brakes will release quicker (hence your slightly faster takeoff) and your brakes will feel more sensitive. The clutch on these cars are somewhat hydraulic, and use the fluid from the brake system. Pumping your brakes also makes the clutch work a little better.

If you haven't done this in the past two years, get your brake fluid flushed! It isn't a difficult job if you have some tools. If you have had the brakes flushed according to schedule, check your brake lines. Could be losing pressure somewhere.

 

[TDI Power]

Changed my fluid about a year ago, but now that you mentioned the clutch, yes it feels better too after pumping the brakes, it also grabs higher. Sometimes the clutch will grab all the way at the bottom, then after pumping the brakes, it will grab higher.

Checked out all my lines and no leaks, could it be a bad master or slave cylinder, clutch or brake? Thanx

 

[Peter Cheuk]

Hmm, I think that pumping the brake pedal is working out your right foot so what you are experiencing is that your right foot has more strength to press the pedal and so it does it more hence the "increased power". In other words, I don't have a clue why your car is quicker when you pump the brakes.

 

[TDI Power]

Peter, LOL, nice try

. Its, weird, the brakes are fully released because when I stay at the slightest incline the car wants to roll the same way if I pump the brakes or not.

I wonder if it has anything to do with the brake booster, after pumping the brakes, maybe there is less load from the vaccum pump on the engine?

 

[Peter Cheuk]

I tried it the other day and it did not seem to make any difference in power on my car. I did notice that the throttle pedal felt lighter after pumping the brakes, though.

 

[TDI Power]

Thanks Peter, good to know its not normal. I'm also starting to notice after pumping the brakes, when I keep pressure on the brake pedal, the pedal slowly sinks about an inch. Will have to investigate more.

 

[tdibeliever]

SOund to me like your Master cylinder is failing, or you have air in the system. I'd suspect it's a bad M/C first. The fluid is flowng by the worn piston seals causing the pedal to sink.

 

[TDI Power]

Thank you for all the help guys, got a new master cylinder, now I have to find time to put it in. See if that will help.

 

[Peter Cheuk]

Did you go with stock or the VR6 one? The VR6 one is supposed to be bigger, resulting in a firmer brake pedal.

 

[TDI Power]

I bought the stock one, and cant return it, special price. Didnt even know the vr6 one would fit?

Learn somethig new everyday!