Brakes Not Working

[Dave Ed]

Hi,

My exmo failed the mot on a binding calipers so I ordered 2 and have replaced them both.

I've bled the system and even bled the rears just to be sure.

 

I've now got massive pedal travel and can't lock the wheels at all.

I've double checked everything and can't find anything wrong.

I can see the front calipers flexing as the pedal is applied so I know there is pressure there.

 

As I never had excessive pedal travel before and all I have touched is the front calipers and these seem to be working what else could it be?

Could it be that the master cylinder has given up the ghost coincidentally?

 

Standard 1.6 solid disks and standard reconditioned calipers

[Jez Morton]

Are the bleed nipples at the top?

[sj-bradley]

You haven't put the calipers on the wrong side by accident. Is the bleed nipple higher or lower than the brake pipe?

 

Sounds like there is still air in the calipers which you haven't removed.

 

Simon.

[Dave Ed]

Hi guys.

I've double checked against the old ones and online and my Haynes manual. Im adamant they are fitted correctly and the bleed nipples are at the top.

I'm sure it's just air but I've tried 3 Times now and still have the travel in the pedal

[Guest zerorace]

silly question but how are you bleeding them.

 

[Guest Ian & Carole]

Have you got rubber or braided flexi hoses?

 

If rubber protect one at a time with a bit of card and nip each one in turn and check the pedal travel.

 

You will be able to isolate where your problem is.

 

You can nip both fronts and if your pedal is hard then you still have air in the system. If the pedal is soft and long on travel then I would start to suspect master cyl. failure.

 

One other tip is to force the pads all the way back into the callipers and wedge them there again check pedal travel, if poor try bleeding while pads are held in this position.

 

HTHs

[Dave Ed]

I'm bleeding the new usual way, wife depressing the pedal and me slackening or tightening the bleed nipple.

 

Ian, I've got rubber hoses but I'm not sure what you mean by using the card and checking each one in turn.

[jaimo]

means using card to protect the hose squeeze the hose together with pliers or mole grips to block hose

[Dave Ed]

Ah gotcha. I've got a proper hose clamp so will try that.

Am off to try now so will let you know how it goes.

[tractor]

I slacken bleed nipple put a hose from bleed nipple to a bottle of brake fluid then fill reservoir then pump away no need to disturb the wife

[Dave Ed]

Right here's what I found.

 

Although I was keeping a close eye on the reservoir to make sure the level didn't drop too low I think it was still dropping too low.

I seem to remember that Simon and I had the same issue at the Donnington show last year. Anyway I overfilled the res and bled the brakes and now I have pressure.

Once I'd cleaned up I noticed that both bleed nipples were weeping so I gradually tightened until I feared I would strip threads and they are still weeping. I've given the car aquick drive and the pedal is better but still not as good as it was originally.

 

I'll try and get my mot first and then look at replacing the bleed nipples but as these were new reconditioned units I don't feel that I should have to at my own expense

has anyone had a similar experience?

[Dave Ed]

Now that I've had time to think about it, I think the weeping is just residue fluid. It only weeps when the rubber end cap is placed on the end of the nipp!e so i don't think there is an issue after all. Its just leftover fluid in the threads.

 

I still don't have confidence with the pedal travel though.

[Guest 2b cruising]

Could be as you say, trapped in the threads.

Could also be wrong threads and sealing angle on the bottom of nipple.

Degrease them and watch over a couple of days.

If fluid re appears, you have a fault.

If not, relax.

[Snapperpaul]

We had an issue on a Fisher Fury, recon calipers had the bleed nipple hole recut deeper and the bleed nipple bottomed out.

We could not get a good seal until longer bleed nipples were installed

[Dave Ed]

It's not the bleed nipples, I looked this morning and there is no weepage.

I had pressure in the brakes but still quite a bit of pedal travel. Once I started the engine the pedal would then travel pretty much to the floor albeit with the brakes locking.

I think the extra movement is the servo working so I think I'll be investing in a new master cylinder and see what happens.