Still got a brake problem

[BUSHWHACKER]

I suppose, as it's about the only not new thing in the system, it has to be that. But why?

Just to be different? Argumentative? A cnut?

[Albannach]

Just to be different? Argumentative? A cnut?

Aye, that'll be it.

[wishbone]

It will be interesting for me to see how you get on with this as my 2.4 is pretty similar. (Albannach might remember - it was just before I went to Spain in the truck) New front calipers, braided hoses etc. Passes mot fine but not much feel until the pedal is quite far down. I can lock the brakes up fine with a stomp so they do work ok.

I think I'll try changing the proportioning valve too as it's the only thing I haven't really checked either.

Did you have them pressure bled or did they use the vacuum on the bleed nipples ?

Sometimes bleeding the proportioning valve first can help. Don't know why but well worth a try.

Rob.

[yoshie]

It will be interesting for me to see how you get on with this as my 2.4 is pretty similar. (Albannach might remember - it was just before I went to Spain in the truck) New front calipers, braided hoses etc. Passes mot fine but not much feel until the pedal is quite far down. I can lock the brakes up fine with a stomp so they do work ok.

I think I'll try changing the proportioning valve too as it's the only thing I haven't really checked either.

Did you have them pressure bled or did they use the vacuum on the bleed nipples ?

Sometimes bleeding the proportioning valve first can help. Don't know why but well worth a try.

Rob.

We tried every option mate, we have a vacuum bleeder and he also put it into garage for a pressure bleed.

[Albannach]

I do remember, Rob. I can't see why the PV would cause a long pedal, but I'm possibly not understanding how it works on a Surf.

Alan's had his brakes bled every way possible! The best result, the way it is now, has been Pressure Bleeding.

My 2.4 always had soggy brakes, until a pipe burst. When that was replaced the brakes were perfect. My 3.0 had a good pedal, until I replaced the front pipes, now it's a brilliant pedal. Surf brakes just seem to be tempremental.

[wishbone]

Same as me then - I spent 4 nights bleeding them over and over, bled the MC first etc. Paid a garage to pressure bleed them and no better. I ended up just getting used to them. As said they do work just pedal travel is not quite right.

Will try and swap in the rear valve from my 3.0 and see if that fixes it.

Cheers,
Rob.

[Albannach]

Actually, after writing what I did and before I've actually looked at the piping configuration, I had a thought!

It may be worth bleeding both pipes (at the LSPV end) going to the LSPV, see if anything happens. Be best to do it under pressure though, take it back and ask them to do that.

My thinking is that dual front brakes on a bike can be a PITA to bleed without pressure. The reason they are a pain is that the air in one line prevents the air in the other from pressurising, therefore making them unbleedable. The fix with a bike is to dribble fluid out of the nipples, then tape the brake lever against the grip overnight. The dribbling allows the fluid to displace air, the lever to grip bit allows the remaining air to be displaced. It's worked for me several times.

[wishbone]

Makes sense - I helped Lord Lucan change his brake lines (front to rear) and bleeding normally just wasn't working - couldn't get a firm pedal. We changed the MC and still the same. We then tried bleeding the proportioning valve first and it worked. Maybe a similar thing going on to the bikes brakes?

Other thing I've read that may work is reverse bleeding (from nipples towards MC)

Rob.

[steved]

What's the pedal travel like with the servo exhausted if its ok it may just be the vacuum pump being a bit overenthusiastic its not uncommon on diesel engines there are DVLA MOT bulletins about it, this is 1 discussion about it on the MOT testers forum http://forums.motester.co.uk/forum4/441.html

[knicko]

Have not had to bleed the brakes on my Surf yet, but had similar problems with a couple of previous cars where i had either replaced MC or accidentally sucked air into the MC by not paying attention to fluid levels whilst bleeding.

Despite continuous attempts to bleed through with several bottles of new fluid, just couldn't get the brake pedal to stay firm and stop 'creeping away' under foot pressure.

I only resolved this by bleeding the MC as well as the individual calipers. Although there was no bleed valve fitted on the MC, by slackening the union on the outbound pipe while someone depressed the pedal, bleeding of the MC was achieved and the brake system restored. Keep a close eye on the reservoir fluid level and don't over-loosen the MC union while you're doing this, or you'll have to start all over again.

If it helps and is relevent in your situation ..... good luck!

[KERRSURF]

Have not had to bleed the brakes on my Surf yet, but had similar problems with a couple of previous cars where i had either replaced MC or accidentally sucked air into the MC by not paying attention to fluid levels whilst bleeding.

Despite continuous attempts to bleed through with several bottles of new fluid, just couldn't get the brake pedal to stay firm and stop 'creeping away' under foot pressure.

I only resolved this by bleeding the MC as well as the individual calipers. Although there was no bleed valve fitted on the MC, by slackening the union on the outbound pipe while someone depressed the pedal, bleeding of the MC was achieved and the brake system restored. Keep a close eye on the reservoir fluid level and don't over-loosen the MC union while you're doing this, or you'll have to start all over again.

If it helps and is relevent in your situation ..... good luck!

I already did that.

The brakes are a very good, but still got lots of pedal travel, I'll resolve it when weathers better. A new proportioning valve is going on to see if it helps.

[KERRSURF]

What's the pedal travel like with the servo exhausted if its ok it may just be the vacuum pump being a bit overenthusiastic its not uncommon on diesel engines there are DVLA MOT bulletins about it, this is 1 discussion about it on the MOT testers forum http://forums.motester.co.uk/forum4/441.html

I found this post interesting.

"had a merc sprinter where the pedal got to the floor , load sensing valve was then correctly adjusted & the problem solved"

[wishbone]

Well my truck just failed it's mot on rear brakes. Handbrake and normal brakes.

Diff oil in 1 drum so put another halfshaft in and handbrake sorted.

After bleeding the brakes were worse than ever. Pedal could be pushed down to the floor. After bleeding over and over and swapping in another MC I swapped in another Load sensing valve and it fixed it.

Brakes better than they've been for ages.

Rob.