Fb 13 Break System

[sira]

I have nissan FB 13 YOM 1992. it has front disk break and rear drum break system with 4 line master pump. when i applies break it will be applying front disk very much and rear looks not applying. i tested with this on good carpet road how i did was, i reached 50km and applied break. its locked 2 disk (front).i only can see skid marks only front breaks.

i replaced the master pump,booster,and applied the front caliber repair kit.also replaced the rear break cylenders too.nothing to replace now.the problem is still same

is anybody can tell me what is the problem with my car ,the technician who replaced above items, is working in A*W and i think he is good BAS but he cannot rectify the issue.

:):):)

sira

[The Don]

I have nissan FB 13 YOM 1992. it has front disk break and rear drum break system with 4 line master pump. when i applies break it will be applying front disk very much and rear looks not applying. i tested with this on good carpet road how i did was, i reached 50km and applied break. its locked 2 disk (front).i only can see skid marks only front breaks.

i replaced the master pump,booster,and applied the front caliber repair kit.also replaced the rear break cylenders too.nothing to replace now.the problem is still same

is anybody can tell me what is the problem with my car ,the technician who replaced above items, is working in A*W and i think he is good BAS but he cannot rectify the issue.

:):):)

sira

Hi Sira,

Its not unusual to only have skid marks for the front tyres only. I assume your technician has adjusted the rear break shoes and the shoes themselves and the drum is in good order. Inspection of the shoes will indicate if they are engaging properly with the drum.

Your issue seems to be one of break balancing if a problem exists

First thing you have to check is if the breaks are applying at all and doing so satisfactorily and skid marks are not a conclusive test as its quite normal to have more break force applied to the front wheels compared to the back (else the car will fishtail under breaking)

How about tyre condition ? are all 4 tyres the same brand and have the same amount of thread ?

The Don

[sira]

Hi Sira,

Its not unusual to only have skid marks for the front tyres only. I assume your technician has adjusted the rear break shoes and the shoes themselves and the drum is in good order. Inspection of the shoes will indicate if they are engaging properly with the drum.

Your issue seems to be one of break balancing if a problem exists

First thing you have to check is if the breaks are applying at all and doing so satisfactorily and skid marks are not a conclusive test as its quite normal to have more break force applied to the front wheels compared to the back (else the car will fishtail under breaking)

How about tyre condition ? are all 4 tyres the same brand and have the same amount of thread ?

The Don

Hi Don,

Thanks for your quick reply.

all tires are same brand and same model.goodyear india. i did face my drum too. changed the wheel cylinders with new break washers. also i changed the break shoues - FBK.

[GearHead]

i don't know whether this would apply to the specific make of car that is under discussion here, but in my car there is something called 'dual proportioning valve' which distributes the brake force that comes from the master pump to the front and rear calipers/drums....mine had some issues like some oil leaks,etc so i had to replace it and now the brakes seems to be working just fine...ask your mechanic about this and get it checked...other members in the forum might be able to give more info on whether this applies to your car..

[The Don]

i don't know whether this would apply to the specific make of car that is under discussion here, but in my car there is something called 'dual proportioning valve' which distributes the brake force that comes from the master pump to the front and rear calipers/drums....mine had some issues like some oil leaks,etc so i had to replace it and now the brakes seems to be working just fine...ask your mechanic about this and get it checked...other members in the forum might be able to give more info on whether this applies to your car..

I think it applies to all modern cars of the pre ABS Era (I think ABS implements a more complicated system with break force independently controlled for each wheel)

So Gearhead I think you could be right and its probably the dual proportioning valve which is faulty !

Another thing to check Sira is the self adjusting system for the rear brake shoes do not always work so you could try adjusting them or advancing the brakes a bit in the rear and see if that helps

[Pericles]

Two things,

The disk will have more locking power than the drums, so its possible even under heavy braking, the rear wheels will not lock completely.

Weight transfer to the front of the car means the rear will lift and the lower weight means the wheels aren't pressing hard enough to leave a trail of rubber.

Random thoughts, not expert. If your back breaks aren't working the mechanic should tell you anyway.

If you want to check if the rear locks tho, find an empty field and try the test and have someone outside see if the rears lock. Make sure you have plenty of space

[Twin Turbo]

What ever the configuration of brakes you have, all cars have by design have more brake force to the front.But I have seen some makes of brake pads have more friction than others. make sure ALL brake lines are completely bleeded. Start with the rear wheels. and have the rear shoes adjusted with the hand brake cable loosned. then adjust the hand brake, not the other way round. your car does not have ABS so the wheels getting more pressure (Front) will lock, make sure in the car still skids to a stop in a straight line when brakes are applied in testing. And I don't have to mention the importance of using good quality brake fluid. Replace brake fluid every two years.

Happybraking.

[sira]

What ever the configuration of brakes you have, all cars have by design have more brake force to the front.But I have seen some makes of brake pads have more friction than others. make sure ALL brake lines are completely bleeded. Start with the rear wheels. and have the rear shoes adjusted with the hand brake cable loosned. then adjust the hand brake, not the other way round. your car does not have ABS so the wheels getting more pressure (Front) will lock, make sure in the car still skids to a stop in a straight line when brakes are applied in testing. And I don't have to mention the importance of using good quality brake fluid. Replace brake fluid every two years.

Happybraking.

Many thanks all of you.

I did the small expeiment and it was suceed. i grind the middle surface of the break shoue with sand paper.normally when you see the 2 break pads 9 after installed new shoues) you will the sheeted area gets worn out.just grint that area, now the shoues will be sheet whole face and break condition became good.

thanks all of you

[The Don]

Many thanks all of you.

I did the small expeiment and it was suceed. i grind the middle surface of the break shoue with sand paper.normally when you see the 2 break pads ( after installed new shoues) you will the sheeted area gets worn out.just grint that area, now the shoues will be sheet whole face and break condition became good.

thanks all of you

Hi Sira,

So it was uneven wear on the rear drums ? causing the shoes to not seat properly or was it the shoes themselves ?

The Don

[sira]

Hi Sira,

So it was uneven wear on the rear drums ? causing the shoes to not seat properly or was it the shoes themselves ?

The Don

Ya i think so.but the given diameter of the drum is 181mm but after facing the drum the drum is 180.5 mm. as i mentioned above,m after greind the pads looks ok but another hicups, when it cool it is perfect but when it warm break not good. i thisk the drum has special layer for break shoues. i heard that on the internet too. think repace with the secound hand and see the difference

Sira

[The Don]

Ya i think so.but the given diameter of the drum is 181mm but after facing the drum the drum is 180.5 mm. as i mentioned above,m after greind the pads looks ok but another hicups, when it cool it is perfect but when it warm break not good. i thisk the drum has special layer for break shoues. i heard that on the internet too. think repace with the secound hand and see the difference

Sira

If there was metal on metal contact with the brake shoes and drum there might be uneven or excessive wear on the inside of the drum which might not be helping the situation either !