Alright I really need help with this one because I've exhausted my resources. Here is the issue, I bought my 1993 del sol si about a year ago from a friend of mine. After driving it for a while I realized that the brakes were very spongy and at a stop light the brakes would sink to the floor. Alright, well we replaced the master cylinder and 3 out of 4 calipers, the master cylinder was bench bled and the system was bled several times. The master cylinder was a remanufactured one from advance auto parts because the dealer around here is a dick to deal with. Alright, well the pedal does not sink to floor anymore, however, i still have only about a half pedal that is really spongy. Therefore, we bled the brakes again, still spongy. Here is where it gets weird; when the car is off I get a full brake pedal but as soon as I turn the car on I lose that pedal almost entirely. We checked the vacuum lines to the booster and they were fine, but for the sake of knocking off possibilities we replaced the power booster. After a few hundred dollars later my pedal is till really low and spongy, If you disconnect the brake booster through the vacuum line it gives me a full pedal but as soon as you hook it back up I lose that pedal. For reference, I have no leaks in the lines because I check the fluid all the time and I never lose any. I really need help because I can't figure out with to do to regain my brake pedal, I've tried everything....
HELP!!!!1993 Del Sol Brake Problem
- Thread starter rlazier07
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welfare
Ancient Member
did you check the valve that is on the booster vacuum hose? I believe it is a 1 way valve, it has an arrow that points to the engine, either way it's prolly like 5 dollars through honda, Just a suggestion, I have never seen one go bad, nor have I seen one installed backwards, but hey anything's possible.
yeah man i thought the same thing we actually took the vacuum line off there and we had vacuum, so that is working fine. The weird part about the whole situation is that when u disconnect the vacuum to the booster you get a stiff brake pedal, when you put it back on the pedal sinks again. That's why i was thinking the booster, however, after replacing all of that and checking the vacuum lines it's not the booster. Stupid me, however, decided to paint the new booster because they always just hit it with that crap primer that rusts right up, but I believe I cannot return the part if i paint it. We rebled the master cylinder and the brakes again and still nothing as well.
Yeah that's what we were thinking because today I took it to my uncles house, because he is a mechanic who does a bunch of sidework, plus he has a lift and a nice garage(better than rolling on the ground). We adjusted the rod on the power booster, but that just made the pedal harder to push without making the brakes any better. Then we took the master cylinder back off and re-bench bled, the master cylinder. Put it back on the car, made sure there was no air in it, re-bled the calipers all the way around and I think the pedal actually got a little worse. It's really weird because even he has no idea unless the master cylinder is faulty. We also went to the (I believe it's called the proportion valve) where the two lines turn into 4 and bled that. Still nothing.... We just can't figure it out. Also, we noticed that there is no drag at all on the rotors from the calipers; normally you get a little bit of drag nothing overbearing but a little bit, it seems like the pistons in the brake calipers are completely disengaging. It's really weird because I rebuilt a 1993 eclipse and never had any of these problems with the braking system and I redid the whole system. Haha yeah all the calipers are on the right way, sorry for laughing but damn if you put them on the wrong way shouldn't be allowed near a car. Nope no abs, I don't like it and I'm glad I don't have it. Thanks man I just can't figure this one out.
93delsolsi
Junior Member
Had the same problem on my del sol i put a type r brake booster and ss line in the front and now stops on a dime
I took the master cylinder off and brought it back to advance, swapped it for a different one, and still no brake pressure. The car will stop but the pedal is almost against the floor when it does. Two bad master cylinders? I just have no idea anymore Is there a place I can go to get a high performance master cylinder to try and push more pressure into the lines? Where did you get the type r booster? and sorry I suck with acronyms what do you mean by ss lines?
welfare
Ancient Member
I assume you have disk brakes all the way around, how well does the parking brake work? That may narrow it down since the parking brake uses the rear calipers, if the parking brake works really well then your problem can be narrowed to the front.
The thing about a brake system is that it is closed, it should never make a soft pedal unless there is air in the system, the fliud is getting past a seal somewhere or one of your rubber brake lines is bubbled and when you press the brake it bulges out.
You say that you replaced 3 of the calipers, the booster, the master (twice) and you bled.
Bench bleeding the master is very important, just to be clear I want to make sure that you did it correctly by putting it on a level surface, or in a vice, and used a screwdriver or the like to push the punger ALL THE WAY in, over and over until the brake fluid coming out is clear (bubble free)
Then with the bleeding the brakes you start at the right rear caliper, have someone pump the pedal 3-4 times and then hold pressure ont he pedal while you open the bleeder and then close it when the other persons foot reaches the floor, then repeat procedure until there is clear fluid coming out, In your case where you replaced the master you would have to do this probably 5-6 times at each wheel to make sure that the air that got trapped at the master where the lines go in comes out the bleeder.
Repeat the pump/open/close at the left rear, then right front then left front (furthest to closest to the master)
You should easily use about a quart of brake fluid to bleed the whole system
Worst comes to worst bring it to somewhere where they can take a look at it for you.
You never did answer my question as to if you have ABS on that car or not, it doesn't really matter, but some ABS units have bleeders on them to save from having to bleed all the way to the calipers in the event of a master replacement.
If you live near albany, NY I would be happy to take a look at it for you.
The thing about a brake system is that it is closed, it should never make a soft pedal unless there is air in the system, the fliud is getting past a seal somewhere or one of your rubber brake lines is bubbled and when you press the brake it bulges out.
You say that you replaced 3 of the calipers, the booster, the master (twice) and you bled.
Bench bleeding the master is very important, just to be clear I want to make sure that you did it correctly by putting it on a level surface, or in a vice, and used a screwdriver or the like to push the punger ALL THE WAY in, over and over until the brake fluid coming out is clear (bubble free)
Then with the bleeding the brakes you start at the right rear caliper, have someone pump the pedal 3-4 times and then hold pressure ont he pedal while you open the bleeder and then close it when the other persons foot reaches the floor, then repeat procedure until there is clear fluid coming out, In your case where you replaced the master you would have to do this probably 5-6 times at each wheel to make sure that the air that got trapped at the master where the lines go in comes out the bleeder.
Repeat the pump/open/close at the left rear, then right front then left front (furthest to closest to the master)
You should easily use about a quart of brake fluid to bleed the whole system
Worst comes to worst bring it to somewhere where they can take a look at it for you.
You never did answer my question as to if you have ABS on that car or not, it doesn't really matter, but some ABS units have bleeders on them to save from having to bleed all the way to the calipers in the event of a master replacement.
If you live near albany, NY I would be happy to take a look at it for you.
Nope I don't have ABS, thank god I really don't like them. As for the brakes we bench bled the master cylinder that exact way twice, I even took it to my uncle's who used to work for a really reputable shop around here. He bench bled the master cylinder again and rebled the entire system, including all of the calipers(yeah pump 4 hold, pump hold, it's been my night, every night this week and have gone through 2 quarts, cleanest brake fluid in the lines i've ever seen). We ran all of the lines and there is no leaks, we aren't losing any fluid at all. I called a tech support guy regarding the master cylinder and he said it may be a faulty Proportion Valve, however, those things are damn expensive 257 dollars(I'm a college student that's a lot of money), would that be a possibility? I'm at a loss man I just can't figure this out. I would take it to a shop but I've had three certified mechanics look at it and they have no idea, If i take it to a shop they are liable to charge me a ton. I live In sullivan county right outside of liberty , however, this weekend I'm headed back up to College at Ithaca. My car will stop but the pedal is so low it feels unsafe, I've been driving with it for a year and I'm starting to get irritated.
welfare
Ancient Member
wow, that's annoying, I would be pissed if I was you.
Ok, as far as the prop valve goes, I doubt that it is that, the prop valve doesn't do anything except restrict flow to the back brakes, and it can't get air in it because it is part of the brake system and it would have gotten bled with the rest of it. that and I have never seen one go bad on a honda.
Next 2 thoughts:
did you check the pedal adjustment, it's under the dash, there is a little threaded rod with a locknut similar to a tie rod end, maybe that is out of adjustment, you can try to work it until it feels better,
The second thought is about the cap on the master cylinder, do you have it off when you are bleeding, I generally leave the cap off unlesss it is one of those master cylinders that spray fluid everywhere, Honda's can be bled with the cap off, it prevents vaccum from building up in the resivoir during the bleeding process.
Just a couple thoughts, other than that I have no clue at all, sorry
Ok, as far as the prop valve goes, I doubt that it is that, the prop valve doesn't do anything except restrict flow to the back brakes, and it can't get air in it because it is part of the brake system and it would have gotten bled with the rest of it. that and I have never seen one go bad on a honda.
Next 2 thoughts:
did you check the pedal adjustment, it's under the dash, there is a little threaded rod with a locknut similar to a tie rod end, maybe that is out of adjustment, you can try to work it until it feels better,
The second thought is about the cap on the master cylinder, do you have it off when you are bleeding, I generally leave the cap off unlesss it is one of those master cylinders that spray fluid everywhere, Honda's can be bled with the cap off, it prevents vaccum from building up in the resivoir during the bleeding process.
Just a couple thoughts, other than that I have no clue at all, sorry
Yeah man I really really appreciate you taking the time to respond because I have no idea at all. I guess I'll just run it as is until i get enough money to take it to a brake shop. We even used a vacuum bleeder on the lines but nope no improvement, yeah we adjusted that rod it made the pedal hard but that just made you have to put forward more effort because the pedal was hard but still had to be pushed 3/4 of the way down to stop the car.
Yeah, i'm still driving it around with the low pedal because I'm away at college and don't have the tools to swap brake lines until i go home for a break. It seems like this is a typical problem with the del sol's from what i've been reading. I'm kind of curious as to why?
welfare
Ancient Member
it wouldn't make any sense that it is only a problem with the del-sol, all of the parts are the same as a civic ex except some of the metal brake lines, which don't go bad unless they rust out, in which case they would be leaking.
Either way, if you do figure it out please let me know too so that I can have a little something to add to the knowledge base.
Either way, if you do figure it out please let me know too so that I can have a little something to add to the knowledge base.
Yeah, man the reason I say it seems like a common problem in the del sol is because I've talked to a few people with del sol's and my friend even just bought a 1993 del sol s, with the exact same problem. So as you said it could have something to do with the brake line setup after a while.
NORTHSTREET
New Member
I am having the same problem on my girlfriends Civic Lx non ABS. I went ahead and changed the master cylinder 3 times and finally buying a new one, brake booster, caliper and brake hose and adjusted the pedal with no luck. The car has been bled and it has stomped everyone at the shop. When anyone finds out anything let me know.
