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1992 Loyale Spongy brakes that sink to floor weird happenings...


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Hey guys I am trying to figure this out.  My folks' car is a 1992 Subaru Loyale Automatic 4wd.  So they were telling me the brakes were getting more and more spongy, when I came to visit them and checked out the car the pedal would pretty much go all the way to the floor.  Now I had done the front brake pads about six months before this all occured, and the calipers lookes fine when I changed the pads, the pistons went back in without any problems.  The back brake shoes looked fine so I didnt bother changing them and I didnt see any wet spots around the rear cylinders.  Back now to six months later and the pedal sinking to the floor.  I checked the brake lines and they looked fine.  I was now convinced its the master cylinder.  I did some tests I saw here on the forum.  I went ahead and bled the brakes first to make sure there was no air, the brakes were still spongy maybe a tad better but still going to the floor.

Ok so I went to Autozone and got a remanfuactured master cylinder, about 40 dollars which included the 8 dollar core charge.  Not having a tube wrench I ended up stripping one of my brake line bolts but I managed with a vice grip to get it off.  Needless to say I went to Sears to get one for 10mm but ended up with a set of 5 for 35 bucks since they didnt sell individual ones, they are definitely the right tool for the job.  Okay so putting the new one on I managed to strip the threads on the rebuilt master cylinder, so I ran and bought another remanufactured one and managed to get it in, but it was a b!@tch.  I did bench bleed it before.  Okay so went through and thoroughly bled all the brakes, no improvement.  Went back bled the brakes again the next day brakes were still like crap with pedal sinking all the way down.  I was at my wits end.  I decided to adjust my parking brake to have some sort of good emergency brake if I needed to take it in.  As I was adjusting the parking brake and following the procedure which has you pulling on brake and testing the pedal, my brakes started to firm up.  I did this repeatedly and lo and behold the brakes went back to almost normal.  I was reading somewhere about hill hugger assist feature on some subarus and that can be a problem with spongy brakes but I looked on youtube and it seems to be a feature only of cars with a manual transmission.  There was also something online about break distribution system etc but I didnt see anything for the loyale. I also dont think it has ABS, I dont see anything there fancy except just a plain master cylinder.

So my question is what is going on here, I am worried the spongy brakes may come back unexpectedly.  I really want to know what the problem was.  Was it the MC is it something else going on.  Does this car have a HH system and brake distribution switch that could also be causing brake pedal to go to the floor?  HELP!!

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I have not seen ABS on any Loyales.   You are correct, hill l holder is an option on standard shift transmissions.

 

Check all the brake hoses by looking at them while someone else mashes the pedal.

 

There is a balancing valve of some sort mounted under the car near the tube that the rear wheel arms attach to.  I do not know if it can cause your problem.

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http://www.classicperform.com/TechBook/BrakeTroubleshoot.htm#spongy

http://www.mbmbrakeboosters.com/index.php?option=com_content&view=article&id=6:proportioning-valve-faq&catid=2:brake-boosters&Itemid=10

I did some search on that valve you mentioned, the brake proportioning valve, and it seems like it can cause the symptoms, what is strange is that an unadjusted parking brake can also cause that,  I have never come across that phenomenon of a parking brake giving pedal travel to the floor.  Very bizarre stuff here.

Thanks for the tip.  That first link has  a nice list of diagnostic possibilities I found in my search.  The second talks about different valves.  I never realized there was that much stuff to brake systems.  I always thought just MC, lines and calipers.  Didnt know about all these valves etc.  Just adds to the diagnostic difficulty.

Edited by capmarvelous
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When you compressed the front brake caliper cylinders back in, how did you do it, with a c-clamp and just push them in?

If so you have probably damaged them and need to replace them. They're designed to turn in. Hopefully that's not what happened though.

 

 

Also, one leading cause of spongy brakes on the Loyale is because nobody adjusts the rear brakes. They don't auto adjust like most cars do (even the older GLs had auto adjusters). You have to raise the rear of the car with the tires still on. There's a post sticking out of the rear of the drum backing plate, it may still have the protective rubber sleeve on it. The post is the adjuster. I think an 10mm wrench fits it but I'm not sure. Tighten it a little bit at a time and spin the rear wheel. Get to where the shoes are lightly dragging and back off a bit. Do the other side.

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on my gfs civic her brakes were spongy , we simply replaced the brake pads (all 4) and it dissapeared, ive always had alittle sponge on my 89 GL wagon, took me a while and testing if the brakes were rubbing but i got it perfectly, when i step on the brake it only goes down to exactly where the accelerator pedal rests, theres a nut behind the brake pedal to calibrate, it might help some, just DO NOT OVER DO IT!!!!!! it will overheat your brakes and your braking will suck and you will have glazed brakes, the way i did it was i pulled and pushed my car while calibrating it to make sure it was free but as close as possible, drove it around for 30min, and felt if the front wheels were any hotter than the rear, if you can't hold your hand on the wheel for more than 2seconds, you over did it, also i doub't squishy brakes would ever come back, i had an issue where my brakes wouldn't release when i was ln a hill couple days ago, turns out my hill holder failed on me. so its now disconnected. check your rear brake adjuster also

Edited by Subasaurus
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I75EYA yep I was using a big plumber's wrench to try to squeeze them in couldn't figure why the first one didn't go in then got online and found out the rotate in lol.  So one got squeezed a bit the other went in normal.  However they were both fine after that for a good week cause I test drove it while I was at their place, car didnt pull to one side etc and they didnt complain about the spongy braking till months later.  Then the question is why did it get better with the parking brake adjust, I did it where the cable tightens under the lever in the car when you pull back the plastic trim.  I will adjust them like you said the next time I, its raining right now in Ft Worth and I am leaving their place today.  I will do it the next time through, especially since the brakes now are pretty much ok and the parking brake lever engages ok.

 

Thanks Subasaurus and Tom Rhere, I didnt know I could also adjust the brake pedal also from under the dash.

 

Right now the brakes are good, could the back brakes have somehow adjusted with me constantly pulling on the emergency brake lever and pressing the pedal while I was adjusting the tension on the cables under the lever, below the plastic trim beneath it?  I am just worried that the problem may come back out of the blue.

Edited by capmarvelous
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The e brake works through levers on the front calipers. All of the 4WD wagons I've had have auto adjusters on the back brakes. They adjust when you go backwards, and hit the brakes. If they were rusty and stuck, that would probably make the pedal lower progressively as they wear.

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The proportioning/ balancing valve on the rear end can be by-passed.  I had one rust off, and now I just run a generic T fitting.   Been running it for a long time like that without issues.

This is wrong. The pro portioning valve does not split the line like a T. It's 2 lines in, 2 lines out.

 

It balances pressure from both circuits. Subaru uses a dual diagonal system, so each rear wheel uses a separate line from each other.

 

If you just used a t then you either connected the circuits together, or you plugged one off. As long as it doesn't leak it will work but you have uneven braking action. No really the way to do it.

 

Hillholder can be replaced with a T as it splits one line to go to the F.left, R.right line.

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I75eya, I was thinking about what you said and what Subaru nut said about the e brake being attached to the front calipers (I thought it was the back from other car experience).  When I had squeezed on my right caliper (passenger side) about six months ago I had gotten it down half way with my pliars when I couldnt do any more I got online and found out about the rotating caliper stuff and the special tool needed.  The rest of the way she went in properly, and the driver's side caliper I did all normal with the correct tool, I didnt think anymore about it because the car was braking ok.  Two days ago when I was adjusting the e brake I noticed that the little bar that the cables attach to was tilted quite a bit towards the passenger side cable as if it was pulling it more.  I dont know if its normal or if its a balance issue due to maybe the caliper being partly damaged (though the car brakes fine and doesnt pull to one side or the other)

I am now thinking what if half of the motion of the caliper is damaged, so the first part of the caliper piston going out is ok due to being rotated in correctly when I did the brakes, but as the brakes wore down these past few months it got to the range of motion that could of been compromised by my clamping down on it and trying to push it in.  Now maybe this could of affected the brake pedal eventually in a mechanism I dont know how, but made it sink to the floor and ruined by ability to brake simulating a MC going out type problem.  Then maybe as I was adjusting the ebrake the constant pull on the ebrake lever and brake pedal pumping somehow got the piston to be normal again.  Bleeding it earlier on I didnt see any strange behavior in the brake fluid coming out or lots of air bubbles compared to the other wheels.

If this problem manifests itself again I will replace that caliper I had clamped down for half its range before using the proper tool.  I am pretty sure it was the passenger side front caliper (since the rears are drums).

The adjustment of the ebrake and some brake pedal pushing back and forth had fixed the sinking to the floor brake pedal problem.  I think you are on to something about that caliper being damaged somehow.  This would explain the messing around with the ebrake and the recovery of the brake system.  The weird thing is how is the caliper compromised inside and how could it just mess up my entire braking system so that my pedal would completely sink to the floor?

Needless to say I have learned a bit about the subaru braking system from you guys on this and other threads I looked up.  I appreciate it.  If the problem comes back I will change that caliper and let you all know if that was it.  When I go back to my folks in a few weeks I will adjust the back brakes like you guys said, ie how Subaru nut suggested since its 4wd.  I am just thankful the brakes are working again.  It was very stressful and discouraging changing a master cylinder and then thoroughly bleeding the car twice and still having no brakes and being under time pressure since I had to leave and I didnt want to still have my folks with a nonfunctioning car (though they have another car its always good to have both working)

Now I am starting to feel better, I have a working hypothesis that makes sense based on previous actions and current actions and a plan of action for the future.

Edited by capmarvelous
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so now you are gonna have to get the oldies to sign up and carry on in your absence ??

 

No one has asked the bleed sequence - it seems to matter sometimes with these diagonal split systems

I know EA81 are edit on RHD !! right rear, left fron, left rear, right front, then I do the beed nipples on the master.

 

Think EA82 differs, about to find out soon

 

Also use one man bleeder of tight on nipple rubber tube about 50mm long, then clear tube into an old plastic drain bottle, watch for bubbles, also use thread tape on nipple thread.

 

The masters can be bastards to bleed up on bench. I made up from old metal lines to clear PVC to dribble back to reservoir and won out !

Edited by jono
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Hey New User

I have seen some people give a sequence here.  I used that one for my first bleed.  Second time around I used the one from Autozone web site.  Both didnt do anything for my sinking brake pedal.

actually ....it is jono ...New User apears above your mugshot as well :)

 

Did I use enough emphasis on bastard ? Having to screw EA81 master pipe nuts upside down for starters is against the technician, let alone the odd tension the steel line adds to the equation of lining the threads up to avoid stripping, all the while one bar pressure is working against you tryin' to let air in fresh bench bled master, and gravity is tryin' to let brake fluid (icky stuff on being skin and duco) out !!

 

I found it helps not to bolt master to booster until hard line pipe nuts are in home as it adds to the tension against pipe nut threads. If I had to try do one more bleed after my last attempt, I was going for rubber hose replace on those hard lines from chassis to master to speed the install. The threat was good enough.

 

On my recent bleed after fitting new hoses I thought of making a home suction set up. No air transfer hole in PET fizzy drink bottle, just a tight seal on the small ID say 4mm PVC bleeder hose. Use rubber hose on nipple end, clear PVC hose tight fit, squeeze much air from PET bottle and hold squished while fit lid, open nipple with thread taped threads, any nipple blockages cleared out with hand driven drill bit and let PET bottle reform to its blow moulded shape as it sucks fluid through faster and maybe a step better than gravity flow - I rarely use the brake pedal except if no flow. Pumping, or rather slow pump and even slower release of brake pedal can cause air to re enter at the master :(

Edited by jono
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LOL sorry I was not paying attention

Here is the bleed sequence I had used the second time around

http://www.autozone.com/repairguides/Subaru-Coupes-Sedans-Wagons-1985-1996-Repair-Guide/BRAKE-OPERATING-SYSTEM/Brake-System-Bleeding/_/P-0900c1528006755c

FL, RR, FR, RL

which matches this site

http://www.subaru-svx.net/photos/files/YourConfused/40941.pdf

I agree Jono getting on the MC is an exercise in frustration.  I am surprised they dont have some sort of flexible hydraulic lines that can be used.

Edited by capmarvelous
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