Brake servo

[elmartha]

When i first bought my vts the brakes were crap, the discs were worn and rusty and the pads were shot to bits, i replaced them with brembo max discs and brembo pads, they work well, i bled them and they were still spongy. I pulled the plug out of the servo and it made a hissing noise and the pedal went really solid and the brakes were fantastic but every day i find myself having to pull it out to get the brakes back, is it a seal gone or is my servo knackered?

[adamskiTNR]

The brakes would obviously go solid as you are removing the servo assistance from the system. but the force applied to the calipers will be far less unless you are really standing on them. put the pipe back on

[elmartha]

I take the plug out until it stops hissing and then when it stops put it back in, there is a bit of play at the top of the pedal but they are sharp but after about 5 minutes then they go all spongy again

[adamskiTNR]

The "plug" you are taking out. are you talking about the vacuum hose to the inlet manifold?

[elmartha]

Yes that is the one! sorry my bad!

[Ben_SaxoForte]

its supposed to hiss theres vacuum inside the servo so its just filling with air when you pull the plug

[elmartha]

It does hiss, then stops and the brakes are fantastic but i get down the road and they are back to not so good, pull it out and it hisses again

[Ben_SaxoForte]

Thats totally normal for it to hiss when you pull the plug, when you start the engine again it builds up the vacuum again in the servo.. don't understand why it feels better for a while though could possibly have a leak. I've got a similar problem with mine but mine effects the revs on the engine at the same time.. weird one!

[adamskiTNR]

It will feel much firmer, but the brakes will not perform better

[elmartha]

Well the brakes are at the top of the pedal instead of the middle! Much firmer! But what i want to know is is it leaking and if so where from? If anyone has had this problem before :)

[chinkostu]

no its not leaking, the sponginess will be down to either air or you need to adjust the bar that runs from the pedal to the servo. all you're doing by removing the vacuum is removing the servo, like trying to brake without the engine on. why it feels better for a little bit after you reconnect it is beyond me

[rorz_vts]

I'd recommend rebleeding your brakes bud and make sure you do a proper job

[elmartha]

Have been bled 4 times and there was no air in them at all, was thinking of putting better fluid in it so shall do it again then to see if that makes a difference, if not i shall adjust the pedal

[elmartha]

Adjusted the pedal, they are much better, sharp as a stanley knife now :) still going to put some ATE super blue fluid in it and braided hoses