crap brakes

[blaineuk]

the brakes on my 400 have lots of pedal travel, any ideas on how to reduce this. so far i have rebuilt the master cylinder, fitted new pads all round, checked all the pistons are free, fitted braiede hoses, changed the fluid 3 times.and adjusted the nut thong behind the master cylinder.any thing i have missed??

[TVRleigh]

the way you bleed them can make a lot of differance,
You may want try a pressure bleeder. or pump the break a few times with the nipple closed, then open the nippe and give it a full travel. then close the nipple before the up travel, repeat 3 times.

Also if you change the rubber hoses to braided ones, that will remove some of the travel.

[dickkark]

slack wheel bearing/bearings could cause this,pushing back the pads, then needing more pedal travel to clamp again.

one of the caliper mounts could be twisted or bent,
is the right master cylinder fitted?
or you could just have air in the system still,is it spongy when appplied or firm?

try pushing down on the pedal until it feels firm then hold a steady pressure on it, if it starts to drop then it`s likely the master cylinderis at fault

also did you notice if the servo was full of brake fluid when you removed the master cylinder?

[blaineuk]

TVRleigh said:

Also if you change the rubber hoses to braided ones, that will remove some of the travel.

done that

[blaineuk]

slack wheel bearing/bearings could cause this,pushing back the pads, then needing more pedal travel to clamp again.
no play in the bearings

one of the caliper mounts could be twisted or bent,
is the right master cylinder fitted?
don't think the cylinder has been changed
or you could just have air in the system still,is it spongy when appplied or firm?
spongey but have put arond 2 litres of fluid through

try pushing down on the pedal until it feels firm then hold a steady pressure on it, if it starts to drop then it`s likely the master cylinderis at fault

also did you notice if the servo was full of brake fluid when you removed the master cylinder?
no, but have put new seals in just in case


[/quote]

[Gandalf]

blaineuk said:

TVRleigh said:

Also if you change the rubber hoses to braided ones, that will remove some of the travel.

done that

You could always try the new Wedge 400 Performance Driving Boots Blaine - I`m hoping to get a pair before Rockingham, just so I can see over the steering wheel!

[adam quantrill]

How do you use your brakes? I always make sure I give them some stick when coming down from national speed limit into a 30, braking late and hard. This usually happens about 4 times a day, and seems to keep them in fine fettle.

[350zwelgje]

As posted before, if everything is ok, pads out can be the case. Had this on mine (front 300mm discs): too much wheel bearing play made that the pistons are pushed back too far and made first time more pedal travel required. Changed front bearings (they were old and not proper adjustable anymore), have as minimal play as possible and it is fine now.

Other possibility: If you ever changed the front discs, it is possible the discs are not sitting true with the hub face. This could cause the same issue as above.

Rob

[Wedg1e]

blaineuk said:

and adjusted the nut thong behind the master cylinder.

I think that's the problem. You have too much elasticity in your thong

[leorest]

Wedg1e said:

blaineuk said:

and adjusted the nut thong behind the master cylinder.

I think that's the problem. You have too much elasticity in your thong

I concur. Tighten your thong and tweak yer nipples.

[blaineuk]

350zwelgje said:

As posted before, if everything is ok, pads out can be the case. Had this on mine (front 300mm discs): too much wheel bearing play made that the pistons are pushed back too far and made first time more pedal travel required. Changed front bearings (they were old and not proper adjustable anymore), have as minimal play as possible and it is fine now.

Other possibility: If you ever changed the front discs, it is possible the discs are not sitting true with the hub face. This could cause the same issue as above.

Rob

not this as the pedal will not pump up hard even when cas is not moving.

[adam quantrill]

What happens if you run it with no vacuum (engine not running), does it get hard then (ooh err)?

If it's still spongy there's definitely a problem, maybe a fluid leak.

[.Woody]

mine gets hard every time I use a vacuum!

Sorry couldnt resist that!

My brakes on my 400 dont work until the end as well, they seem to have some contact as soon as I touch the pedal but dont do anything until further down, is that the same, I'd like to sort mine out too.

[TVRleigh]

I've said this before, but how you bleed the breaks can make quite a differance.

[blaineuk]

think it is air in the system, badred is bringing a pressure bleed kit for me to try.

[BadRedWedge]

blaineuk said:

think it is air in the system, badred is bringing a pressure bleed kit for me to try.

Sorted for Tuesday AM matey I will ring you when I get in the area

[blaineuk]

all sorted, only 4 hours to get all the air out and a decent pedal. think need some better pads to give more bite.

[combine]

Good to hear thats sorted , you won't be needing that griff then ?

[TVRleigh]

As said its surprizing how much travel you can remove by used a pressure bleeder, you can do with out, but you have to pump the system up before each open and close of the nipple.
I'll be doing mine tomorrow. if the pressure bleeder arives, as my old one is broken

[blaineuk]

steering rack is now leaking, how happy am i.