10 replies to this topic

[Gremlin]

I've fitted me hydraulic handbrake and we're having trouble bleeding my brakes, we've plumbed it in like so:

 image.jpg   42.88K   49 downloads

The angled union is the input from the foot brake master cylinder via the standard PDWA valve, and the straight union at the end goes to a T piece and to the rear brakes. However upon bleeding it's as if air is getting in

Any thoughts, thank you

[sledgehammer]

I wonder if you bleed the unions first following the brake line back towards the rear cylinders ?

 

you should see / hear the air weeping out 

 

is it a track car ?

Edited by sledgehammer, 08 March 2014 - 06:11 PM.

[Gremlin]

I don't understand what you mean, there is not a bleed nipple on handbrake cylinder.

No it's not a track car, I've done it just because - why not? :)

[Carlos W]

Can you bleed it if you operate the foot brake?

How are you going to get it through an mot?

[sledgehammer]

I mean to slacked the brake unions , put a rag around them , press the pedal ,

 

if you don't get air - tighten & move on to the next union towards the rear wheels

 

keep an eye on the reservoir as it's easy to forget & let fluid get low 

 

It's an alteration to the brake circuit - so not sure how MOT is going to pass it ? (not saying some won't pass it)

Edited by sledgehammer, 08 March 2014 - 06:32 PM.

[HarrysMini]

How are you going to get it through an mot?

I would imagine he's keeping the cable handbrake?

[Gremlin]

Can you bleed it if you operate the foot brake?

How are you going to get it through an mot?

Thats what we've been doing, and I'm keeping the cable handbrake

[Gremlin]

I mean to slacked the brake unions , put a rag around them , press the pedal ,
 
if you don't get air - tighten & move on to the next union towards the rear wheels
 
keep an eye on the reservoir as it's easy to forget & let fluid get low 
 
It's an alteration to the brake circuit - so not sure how MOT is going to pass it ? (not saying some won't pass it)

I'll try it thanks

[Gremlin]

How are you going to get it through an mot?

I would imagine he's keeping the cable handbrake?

You've got it

[tiger99]

I can't see from the picture exactly what you have done, and am assuming that it is plumbed the only way that can possibly work, with the feed from the PRV going in where the reservoir would be, and the output to the rear brakes from the normal outlet on the new master cylinder. If that is so, and it will not bleed, it is possibly due to the pipe layout, as if there is a high point in which air can become trapped, it will take a very large amount of fluid displacement and a high flow rate to shift it. By using a master cylinder that way, you have only a very limited flow rate and displacement. Even using a pressure bleeder, you will not get a good flow rate, due to the restriction imposed by the small bore of the reservoir port drilling in the master cylinder.

 

There are also serious problems with that installation, and your car in general. Does your insurance company know about what is very clearly a bodge in the brake system? And are you using COPPER pipe, itself unsatisfactory, without adequate support?

 

I could tell you exactly what to do to make it bleedable, but I am not going to do so, and instead suggest that as you clearly do not understand the implications of what you are doing, you return the car to standard specification forthwith, and make the roads safer for us all.

[Gremlin]

Thank you for the advice, as always it was an engineering challenge and if we can't bleed it sucessfully it will be returned to normal