General New Brakes

[Code Breaker]

Hi all, ok during mot I was informed as vehicle been stood and will need a run to clean off brakes to pass it. I then decided (stupidly or not), to replace all discs, pads and shoes to have all fresh brakes and expect no problems here on, however, now that new brakes are all in, it wont pass mot as they need bedding, the catch is as no mot or tax, therefore I can't drive it to bed them in!

I've never had this issue on all my cars and this is really my first commercial but it seems I've shot myself in foot as can't get mot now and can't drive it!

Any suggestions as I took out a new insurance policy and already lost a month due to this. I can't find anyone with garage/trade plates to use to bed brakes.

 

[The Panda Nut]

Take the pads out and get some fine emery paper. Place the paper on a sheet of glass or the best flat surface available and flat the pads, EVen pressure on the pad and rotate it so hte wear you inflict is even. Once the pades are flat and even it will improve the brakes. Take a drive to the MOT station but go directly there use an appropriate route to give the brakes soem use. Ill bet this will get you out of trouble. Something like 200 grade paper. Ive just dome one of my Pandas and it worked a treat. If you happen to go al bit of a varied route on your way to the teat station, within reason if you are on your way I dont suppose you will have any issues. Its what I would do.

 

[Code Breaker]

The handbrake (also new shoes) is less effective too. I did happen to drive to the mot station via a longer route working the brakes all the way and done this on two separate days still the same they're beginning to bite but not enough to pass, but handbrake is weak

 

[bugsymike]

The handbrake (also new shoes) is less effective too. I did happen to drive to the mot station via a longer route working the brakes all the way and done this on two separate days still the same they're beginning to bite but not enough to pass, but handbrake is weak

Did you explain to the tester that it was all new parts?
As you and @The Panda Nut mention , a long diversionary drive to the next MOT test/retest, I have found driving or freewheeling down hills working the handbrake helps.
Some ECUs won't let you but I used to drive in a low gear with feet on brake and accelerator for short distances (so it didn't overheat brakes) helped as well.
After working with the handbrake, you may need to manually adjust handbrake shoes inside brake drum.
Some times when you examine the brake material it is only touching on a wear ridge until properly bedded in.

 

[The Panda Nut]

The handbrake (also new shoes) is less effective too. I did happen to drive to the mot station via a longer route working the brakes all the way and done this on two separate days still the same they're beginning to bite but not enough to pass, but handbrake is weak

Try disconnecting the cables at the drum end and make sure they hjave decent and equal movement? Hand brake is more likely to be cable or adjustment related. Ive not had issues with drums not working after new shoes other than this.

 

[Code Breaker]

Yes I told them all brakes are new, they can't help. Its a comfortmatic and it doesn't like braking whist driving even very short gentle attempts and it put an error into the gearbox ecu, it stopped speed increase like limp mode so had to start using gears manually. I've cleared this now but haven't driven it to see

 

[Code Breaker]

Try disconnecting the cables at the drum end and make sure they hjave decent and equal movement? Hand brake is more likely to be cable or adjustment related. Ive not had issues with drums not working after new shoes other than this.

Replaced 'both' discs and shoes also pads

 

[Code Breaker]

I was under the impression that new discs and pads work together transferring material from new pads onto the discs to layer a coating to help the bedding?

 

[The Panda Nut]

Replaced 'both' discs and shoes also pads

My last discs clearly needed running in and it would have been 250 miles worht at leats I reckon. Emery paper does the job in 5 minutes. You MUST use care to wear the pad surface flat or you can upset things. Once the pads are smooth you are more than half way to bedding them in. a 10 mile run working them gently should do the rest.

I changed the caliper slider pins and bushes too which really freed the movement as well. £12.50 from big red.com. I will be doing these pins and bushes every time with new discs as the effect was great.

 

[bugsymike]

I was under the impression that new discs and pads work together transferring material from new pads onto the discs to layer a coating to help the bedding?

Some new discs have a coating, but generally I make sure discs/pads/shoes/drums etc are as clean as possible and just put some use into them , but without overheating.
It does sound a bit of a problem with the "comfortmatic" side.
Is there a neutral gear position where you can safely freewheel down a long hill and work the brakes?

 

[The Panda Nut]

I was under the impression that new discs and pads work together transferring material from new pads onto the discs to layer a coating to help the bedding?

No not really. You want the disc and pad to meet face to face, no rough edges. There is no benefit to swarf anywhere near the area. Things need to be clean and dust free. As Bugsymike says coated discs need to clear the coating, nbut this will occur in the first 5 miles. It will effectively vapourise. New Ferodo pads are quite rough, maybe for this very purpose.

I am wondering what typre of disc pads you have used. Some vary a lot in performance terms. It is why I now stick to Ferodowhich are a good make and used as OEM by many manufacturers including Fiat. Hard pads (and discs) may take much longer to bed in. and settle.

Make sure you get the brakes HOT before MOT as they will work much better with heat in them. Not cooked, but well warm!

 

[Code Breaker]

I had the new front discs and pads fitted at a garage, they couldn't/didn't want to do rears so I did these myself, I cleaned everything several times and inspected everything before, during and after fitting.

 

[bugsymike]

No not really. You want the disc and pad to meet face to face, no rough edges. There is no benefit to swarf anywhere near the area. Things need to be clean and dust free.

Just another thought, what make/quality brakes are they?
The reason I say this Some years ago on a Iveco Daily 3.5 tonne twin wheel pick up I needed rear disc/hub/drum combined units and all I could afford was some cheap indian ones on eBay at the time, they did settle in eventually and work well, but not for some time.

 

[The Panda Nut]

Just another thought, what make/quality brakes are they?
The reason I say this Some years ago on a Iveco Daily 3.5 tonne twin wheel pick up I needed rear disc/hub/drum combined units and all I could afford was some cheap indian ones on eBay at the time, they did settle in eventually and work well, but not for some time.

Simultaneous top thinking. Cheap pads may easily be the problem.

 

[bugsymike]

I had the new front discs and pads fitted at a garage, they couldn't/didn't want to do rears so I did these myself, I cleaned everything several times and inspected everything before, during and after fitting.

No disrespect , but are you 100% happy with the assembly.
By the way is it all the brakes with low efficiency, or one specific area?
Do you have the brake reading printout out?

 

[Code Breaker]

I bought them from GSF car parts, rear discs are Delphi (BG4062), fronts are Drivetec (DM4060C)(coated), Delphi Rear shoes (LS1978), Drivetec front pads (DBPPAD2492), Drivetec rear pads (DBPPAD1994)

 

[Code Breaker]

No disrespect , but are you 100% happy with the assembly.
By the way is it all the brakes with low efficiency, or one specific area?
Do you have the brake reading printout out?

All brakes on all corners, and handbrake both sides too, no sorry was shown on their screen and I remember the tester saying they're also 'not locking up' which they have to apparently.

 

[bugsymike]

I bought them from GSF car parts, rear discs are Delphi (BG4062), fronts are Drivetec (DM4060C)(coated), Delphi Rear shoes (LS1978), Drivetec front pads (DBPPAD2492), Drivetec rear pads (DBPPAD1994) and Delphi shoes (DELLS1978)

So nothing terrible then.

 

[bugsymike]

All brakes on all corners, and handbrake both sides too, no sorry was shown on their screen and I remember the tester saying they're also 'not locking up' which they have to apparently.

The percentage readings of all of them would help.
Also whether they were even/balance wise.
How heavy is van loaded, if very heavy it will be harder still for the new brakes to lock the wheels.
Handbrake will be nearly impossible to lock the wheels, from memory 16% efficiency for the handbrake on dual circuit brakes and it used to be 25% on single circuit as handbrake was then looked on as an emergency brake instead of just parking.

 

[Code Breaker]

The percentage readings of all of them would help.
Also whether they were even/balance wise.
How heavy is van loaded, if very heavy it will be harder still for the new brakes to lock the wheels.
Handbrake will be nearly impossible to lock the wheels, from memory 16% efficiency for the handbrake on dual circuit brakes and it used to be 25% on single circuit as handbrake was then looked on as an emergency brake instead of just parking.

I do recall he said its weight was 4300kg (rated at 4.5kgs), its a Mellor minibus