NCT Fail - Brake force Regulator

Frank Drebin

I took the wifes car for NCT today.
It failed because of 'brake force regulator' sticking.:mad:

• Can anyone tell me where to find the brake force regulators.
• Is there one on each wheel?
• How do I free it up so it's not sticking anymore?
• Does the master cylinder have anything to do with this?

I'm pretty handy with cars so if someone could give me some pointers I'm sure I can sort this.

Would appreciate any advice....

DublinDilbert

what car is it? is it a small hatch back?

These are typically used in smaller cars to add just the amount of breaking force applied to the rear wheels so they don't lock up too early. If the back of the car is heavily loaded more breaking force is applied.

It should be somewhere near the rear suspension with brake pipes going in and out of it. It uses the deflection of the rear suspension to adjust the hydraulic pressure to the rear calipers.

Frank Drebin

Thanks for the info DD

The car is a SEAT Cordoba

Should I be looking for plungers or something of the sort. The bloke at the NCT centre said to take the car into a garage and have something greased to lossen it. Can't fully remember what he said but I couldn't be arsed taking it into a garage. I'd rather sort it myself.

When I press the brake pedal I hear this squeaking noise coming from the rear brakes. Could this have something to do with it too?

DublinDilbert

Just pick up a haynes manual for your car it should give you all the info.

I'm not sure where its located on your car. But i would guess it might just need to be loosened up and greased like he said. They know they are not working if they are caked in much etc...

Not sure about the squeaking noise....

tommmy1979

DublinDilbert wrote: »

It should be somewhere near the rear suspension with brake pipes going in and out of it. It uses the deflection of the rear suspension to adjust the hydraulic pressure to the rear calipers.

That sounds dodgy and i'm glad my car doesn't have one

Captain Slow IRL

Frank Drebin wrote: »

Can anyone tell me where to find the brake force regulators.

It should be fixed to the rear axle and attached to the body - the more weight in the car pushes the car towards the ground and allows more fluid to the rear drums. If you chase both rear brake lines, they should both go into the regulator - it should be the lever that's seized. If you use some WD40 and try to move the lever up and down, that should cure it. Two words of advice though:
- The unit may need replacing
- Don't mistake the hand-brake cables for the hydraulic lines! The handbrake cables will go up into the cabin.

Frank Drebin wrote: »

Is there one on each wheel?

No, just the one.

Frank Drebin wrote: »

How do I free it up so it's not sticking anymore?

See point no. 1

Frank Drebin wrote: »

Does the master cylinder have anything to do with this?

They are linked via the hydraulic lines but the master cylinder is at the front of the car and the regulator is at the back.

Captain Slow IRL

tommmy1979 wrote: »

That sounds dodgy and i'm glad my car doesn't have one

They're designed to stop the rear wheels locking up by adjusting the amount of brake force in relation to the weight the car is carrying. They are common on lots of older cars.

Frank Drebin

K. Thats brilliant.. Thanks for all info peeps.. I will have a look at it this weekend and book the car in for the re-test next week...:)

Darragh29

WD40 is your friend OP! Post your brake data up here so I can see if the component is having any impact on braking performance....

DublinDilbert

tommmy1979 wrote: »

That sounds dodgy and i'm glad my car doesn't have one

Why is it dodgy?

The rear bakes on a car only provide up to about 25% of the braking force, the rest is done by the front.

In small light cars the back wheels would lock up very easily due to there being so little weight on them. So this stops them locking up under moderate braking.

The other way of looking it at is, that it allows the rear wheels to provide additional braking if there is weight in the back of the car.

Frank Drebin

I found the brake force reg easy enough. Attached a few pics I took with my mobile.

Gave it loads of DW40 then jacked the car up and down a few times in the hope of lossening it up.

How do I tell if this is working correctly?
How do the tell at the test centre how if this is working correctly?

When I jack the car up and down there appears to be very little movement in the unit

Captain Slow IRL

The orange line should be the direction of travel, with the pivot point (fulcrum) pointed out with the text.

EDIT: Looking at the photo, I'm not sure if you'd be able to move it by hand with tension on it.(Although you might!) If you have the rear wheels resting on the ground, get someone to bounce the back of the car up and down - lie down on the path, clear of the bouncing car, and try get a look up to check the lever is moving.

Frank Drebin

I think this is sorted.

I took the bolt out that attached the unit to the axel.

It turned out that the pivot point was sticking (totaly fused - wouldn't budge).
A whole bunch of banging, pulling and pushing later I freed it up an lubed it.

Re-attached it and put the wheel back on..

Anyway.. I hope that it's ok as it will be retested this week.

Thanks again.. saved me a couple of bob...