Rear brakes soft

[kaarel]

With search could´t find info so making new topic:D

In spring, on every year inspection my 340 cvt failed rear brake test 3 times. Issue is that foot brake is working but weak. on 4th time passed test,but it was like okey old volvo let it be.
(They calculate rear axel mass and wheel resistance during braking or something like that.)
Front axel as it should.
Handbrake good and better than rear axel foot brake. They say rear brakes do not have enough power.

Usually I have problems with handbrake,never with foot brake.

I have cleaned, done bleeding. open up the rear cylinders, done bleeding again.-nothing
in autumn before car went into garage, did test again still nothing. Drove about 2000 km during summer, so standing/ low usage is not involved.

1.Can this be the brake power distributor? https://www.volvo340onderdelen.nl/en/vo ... d=93033317

2. Don´t think that drums are worn, otherwise handbrake would be the issue as well.

Has somebody faced the b.p distributor issue? at least no topic in internet I know that on 200 series they start leaking and that´s why they will be cut out.


thanks and wash hands
Kaarel

[bogbasic]

The first thing I would blame is the hand brake lever which goes through the back plate of the rear wheels. It has a pivot in it which always seizes and this messes up any adjustments.

.

[kaarel]

Yes, have being fighting with that lever. Moved b.shoes and cleaned it, was moving as should.

My thoughts:

1. Try another brake stand, maybe something off with this companies one...
2. 2 years ago brake hose was replaced and new fluid was put in. Maybe new fluid flushed some dirt to brake power disp.?

Kaarel

[Ride_on]

The bias valve (power distributor) should fail with more brakes not less (which can cause dangerous rear locking), mine had siezed with rust after sitting for 15 yrs. Just replaced with a more recently used unit from a car someone was breaking. I don't know if they can fail weak.

I've also had a gummed up lever, had to work alot of WD40 through it before it moved freely.

Trying having someone brake gently with the back wheels off the ground, while you try and turn the wheel by hand or maybe with the engine. Should give you some idea.

[kaarel]

I bought "new" power distributor, but haven´t replaced it yet, due to car is still in garage. Hopefully end of this month, can tell if this helped or not, I hope it will clear the issue.
the handbrake lever was first thing I removed/cleaned and it was ok.
I highly doubt that the master cylinder is faulty.

Will see

[kaarel]

Finally this issue is cleared.
rear brake cylinders and brake shoes replaced. Passenger side cylinder had small leakage under covering rubber.