kleone Posted October 19, 2016 Share Posted October 19, 2016 Hi oldgens I was at the MOT today, and besides broken light bulbs and a hole in the exhaust, the only serious fault found on the car was that my rear brakes are almost non-existant. I have old drums but new shoes. Have adjusted the shoe adjuster thing so I just could get the drums on again. The adjustment brackets are not the kind I see spoken of here in the forum, that can be tightened from the out side, they have to be adjusted before assembling the drums. The pedal feels just as it should, so I cant understand whats the problem, any advice would be greatly appreciated! Quote Link to comment Share on other sites More sharing options...
idosubaru Posted October 19, 2016 Share Posted October 19, 2016 you haven't told us what vehicle - though i can kind of guess... are you talking about parking brake (in the rear) or the actual braking system? we can't see it "rear brakes non-existant" - what does that mean? you should have asked them, not us. pads, shoes, drum, parking brakes, or they're not effectively operating? 1. jack up the car 2. step on the brakes 3. can someone move the tire by hand while stepping on the brakes? 4. if yes - fix it 5. if no - video tape it, ask them, or go somewhere else Quote Link to comment Share on other sites More sharing options...
kleone Posted October 19, 2016 Author Share Posted October 19, 2016 you haven't told us what vehicle - though i can kind of guess... are you talking about parking brake (in the rear) or the actual braking system? we can't see it "rear brakes non-existant" - what does that mean? you should have asked them, not us. pads, shoes, drum, parking brakes, or they're not effectively operating? 1. jack up the car 2. step on the brakes 3. can someone move the tire by hand while stepping on the brakes? 4. if yes - fix it 5. if no - video tape it, ask them, or go somewhere else Yeah sorry for being unclear. The car is a 86 DL wagon. Parking brakes are on the front. When I say "like non-existant" I mean theyre almost nonfunctional. The demonstrated on a brake test roller in the garage, and braking made close to no impact. So theyre not effectively operating. And I cant see why as I put new shoes on last year only. The drums are worn but not at all worn out. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted October 19, 2016 Share Posted October 19, 2016 Seems most likely to me that you have seized wheel cylinders. Hydraulically, the 2 rear brakes are on different circuits, so if the front works, it's almost impossible that it's an issue with a line or master cylinder. Maybe the proportioning valve...but not likely. There are a lot of moving parts in there, and if they don't operate smoothly they can all cause problems. But, usually, if they seize, they tend to allow the brakes to apply at least partially, and then not release. Quote Link to comment Share on other sites More sharing options...
DaveT Posted October 19, 2016 Share Posted October 19, 2016 Do DLS have the same automatic adjusters that GLS do? Gl adjusters work by hard braking in reverse. Quote Link to comment Share on other sites More sharing options...
kleone Posted October 19, 2016 Author Share Posted October 19, 2016 Numbchux- yes I thought of the possibility, but isnt it strange that both would seize at the same time? How can I test its functionability? DaveT- I guess they must be automatic. Explaining the looks of them in my poor english these brackets went across the drum between the two shoes, having a pivoting piece at the one end of each bracket, with a spring mechanism to make them stretch further and longer between the shoes as they get worn. Leaving the difference to the other kind of adjustment brackets spoken of to have the possibility to be adjusted from the outside of the drum manually I will do the brake in reverse procedure and report. If it doesnt bare fruits Ill try swapping the cylinders for new ones Quote Link to comment Share on other sites More sharing options...
Numbchux Posted October 20, 2016 Share Posted October 20, 2016 Numbchux- yes I thought of the possibility, but isnt it strange that both would seize at the same time? How can I test its functionability? Sort of. But they're typically the same age, and under the same conditions, they typically fail at about the same time. Always a good idea to replace calipers and cylinders in pairs. Also, there isn't really any one component that could fail and give low pressure to the rears. The way that Subarus are plumbed, they're on separate circuits all the way up to the master cylinder, at which point you'd have an issue with the fronts as well. They do both pass through the proportioning valve, but even though it's one assembly, it's basically 2 valves in there to keep the 2 circuits separate. Also, proportioning valves very rarely fail, and cylinders do. Quote Link to comment Share on other sites More sharing options...
kleone Posted October 30, 2016 Author Share Posted October 30, 2016 Result: Both rear cylinders swapped with new ones, as they were both leaking. Had to get new shoes as well, cos brake fluid was absorbed into the shoes, so there were no grip 1 Quote Link to comment Share on other sites More sharing options...
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