[Brakes] where did they go ?

[Bootlebarth]

Diesel Multispace reg 2007.
In garage to fit new master cylinder (although brakes seemed OK to me). The garage has had no luck. They achieved a "hard pedal" but road test indicated "No brakes". They have been trying for a week without any luck and now are suspecting the device that allocates pressures to the various brakes. The car has the anti skid feature.
This they find costs over £600 pounds so are looking for a second hand item.

I am wondering if there is a simpler explanation as to why a perfectly good braking system is spannered simply by fitting a new brake cylinder.

Thanks for any suggestions.

[Sol]

Could be they've induced a fault in the abs unit. I'd get it scanned for codes. The abs works by restricting or reducing the pressure to the brake hydraulics. The brakes are supposed to work with no abs of course but maybe it's piped up wrong too at the master cylinder. Or there's a plug fitted to the new cylinder to keep dirt out, maybe they didn't remove that....

[jj9]

Why was the master cylinder changed?


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[Bootlebarth]

Why was the master cylinder changed?


.Good question. I had a failure in the offside rear brake which was replaced. They could not properly bleed the brakes and surmised a fault. They ordered a new master cylinder this would take a month to arrive and I needed the car. They replaced the old master cylinder - there was a somewhat "long" pedal but the brakes worked. I tried the test outlined in the manual which seemed to improve matters. So after trips to Orkney and Northumberland (1000  plus miles) during which I suffered a puncture and discovered a rusted up and virtually unusable spare wheel clamp (what a rotten design). It was back to the garage to sort that out - in the interval the new MC had arrived so they fitted that at the same time - result hard pedal but no brakes!.

[jj9]

Thanks for the info.

I don't get the hard pedal but no brakes bit . . . in my experience you can't have a hard pedal with no brakes working.
I think what may be happening here is, if the engine is off and the vacuum has been exhausted from the servo the pedal will feel hard, however once the engine is started and the servo is working the pedal is a lot easier to press.

If the garage fitted a new master cylinder because they couldn't get the brakes to bleed up after fitting the new rear brake parts (wheel cylinder if drums, caliper if discs) it seems like the new master cylinder has made no difference so wasn't really needed.

I suspect your problem is nothing more than air in the system, the berlingo brakes are notoriously hard to bleed compared to the normal result you get when bleeding a system and the garage is probably thinking there's a problem so is replacing parts.

Many, including myself have suspected a failed master cylinder when the brakes failed to bleed up after replacing parts, turned out air in the system was the cause.


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[brodfather11]

My take on the problem is they firstly couldn't get the brakes to bleed  as jj9 suggests , then decided that as they cant get the brakes to bleed then it must be the master cylinder and possibly fitted it wrong,  quite hard fit the pipework wrong but possible,  or the rod from the pedal/servo unit is not properly in place. That would give a hard pedal but no brakes,   or its the wrong master cylinder and/or in the process of trying to bleed the system have knackered the ABS unit.

 If they sort it out go to another garage in future
They might even want you to pay for it all !

[Bootlebarth]

My take on the problem is they firstly couldn't get the brakes to bleed  as jj9 suggests , then decided that as they cant get the brakes to bleed then it must be the master cylinder and possibly fitted it wrong,  quite hard fit the pipework wrong but possible,  or the rod from the pedal/servo unit is not properly in place. That would give a hard pedal but no brakes,   or its the wrong master cylinder and/or in the process of trying to bleed the system have knackered the ABS unit.

 If they sort it out go to another garage in future
They might even want you to pay for it all !

[Bootlebarth]

Thanks for these suggestions. The garage is an honest local garage in a rural area. I don't think they wil charge for their mistakes (we will see) rather they have allowed themselves to be paniced after the initial decision to replace the master cyclinder.

We shall see.

[ajcommercial]

Hiya, by anti skid feature I guess you mean ABS ? As far as I know ( when I changed the master cylinder on my van ) vehicles without ABS are normal bleeding but with ABS the brakes must be bled using a pressure system, Easybleed or similar, because the ABS unit will not easily pass air and needs constant pressure to pass the brake fluid through, the pumping action of the pedal just oscillates the air to and fro in the ABS unit, this then causes the ABS unit to lock up giving the impression the brakes are bled but actually the pedal feels ok but there are no brakes, i.e the pedal goes to the floor when the brakes are need and the ABS unit either will not work or chatters on and off as if the brakes are locking up. Sadly the ABS unit may not be fixable if it has locked itself because of trapped air... I didn't use a easybleed I just got lucky bleeding the brakes when I fitted a master cylinder..

Assuming they have fitted the correct master cylinder ? there are two types.. Flat reservoir and square reservoir.. My van has a flat one and car has a square one..