Brake Fluid Question

[krnmastersgt]

Never really strayed to this part of the forums but since I'm relatively unsure of who to ask I figured the AT forums would be a cool place to start.

The issue: The car (90 Honda Accord) was running relatively fine (it has some issues that I'm aware of but isn't reasonable to fix for the price) until yesterday when I noticed I had to apply 3-4 times the normal force/distance on the brakes to actually get the car to slow down at all. From what I can see (and what the guys at Jiffy Lube said when I was getting all my filters/oil changed) is that the brake fluid reservoir is basically empty.

After a bit of research I see that it might be dangerous for the overall brake system if I just pour in some new DOT3 fluid as if the system is already almost empty/is empty then the potential air pocket in the brake lines could lead to a fairly catastrophic brake failure (and apparently ABS systems are somewhat more sensitive to this). Not really keen on paying the $140 (quote) for a full brake bleeding and I lack any of the tools to do it myself.

Question is, do I just top-off the reservoir and hope for the best or do I need to go to and have the full system bled? (currently still using the car btw, and when braking seems to be making an almost metal-on-metal screeching sound though its made the sound before when there were no issues with the pads/calipers/fluid levels so 😵)

 

[jlee]

Bleeding brakes only requires a way to get the wheels off, a wrench for the bleeder valves, and another person.

You're not going to make it worse by adding fluid, that's for sure - if it's low enough to suck in air, it's already definitely going to need to be bled.

 

[Bartman39]

Just to add that metal to metal sound needs to be checked for sure...😱

 

[DaTT]

If the pedal feels "spongy" you have to add brake fluid and bleed your brakes. But first, I would find out where the fluid is going. That much fluid doesn't generally just disappear. The metal on metal sound can be one of 2 things; 1) you are actually metal on metal, in which case you will need new parts.....2) could just be the warning tab letting you know that your pads are getting low and you should think about replacing them in the future. The 2 sounds are completely different, but without hearing them I can't be sure.

 

[krnmastersgt]

The sound is a pretty common sound I hear on bigger vehicles as they apply their brakes, and the ol' Accord has made the noise too just not quite as noticeable before as it is now. For now I'm just gonna pour in the bottle of DOT3 fluid I have, drive it around maybe another day or 2 and if the braking still feels loose I'll take it to a shop and have them bleed the whole system for me. As of now I can still use the brakes (just won't be able to do an emergency stop which is why I'm avoiding all the highways) so I don't think there should be too much risk driving it around.

And I wouldn't say it feels spongy, before I had noticeable resistance when I applied the brakes about maybe 10% (first few % just really loose but I blame the pedal not the brake lines) but now I don't get the same amount of resistance without depressing it maybe 30-40%. And to get noticeable breaking while driving at the local 35-45 mph, I'm pretty close to flooring the brakes to get the car to slow down normally.

Last time the system was bled was late 2010 I believe, and while I know brake fluid goes bad I've never had it just up and disappear on me, so I'm fairly certain there is a leak somewhere. Not sure if it's a small one that's been leaking for a year or a somewhat larger one that only recently appeared. I'll check the brake fluid levels every day to see if its rapidly disappearing from the car or if its holding the fluid.

Thanks for the advice.

 

[Squisher]

For now I'm just gonna pour in the bottle of DOT3 fluid I have, drive it around maybe another day or 2 and if the braking still feels loose I'll take it to a shop and have them bleed the whole system for me.

Thanks for the advice.

You were given a lot of good advice, but you don't seem to be taking it.

You are losing fluid, this needs to be fixed. Once fixed the system WILL need to be bled. Doing so as soon as possible is the best advice.

 

[Zenmervolt]

Bleeding brakes only requires a way to get the wheels off, a wrench for the bleeder valves, and another person.

Some cars require that the ABS servos be cycled. This can sometimes require special tools.

For the OP: The car is not safe to drive at this point and under no circumstances should you take the car onto public roads. Until you have found and repaired the leak and bled the brake system, the car should be parked and not used. IT IS UNSAFE.

If you do not have the tools to repair the car yourself, it should be TOWED to a repair shop where the brakes can be brought back into safe operation.

Again, DO NOT DRIVE THE CAR UNTIL THE BRAKES ARE REPAIRED AND FULLY OPERATIONAL. You want to play with your own life, that's fine, but if you're taking the car out on public roads you're putting other people in danger.

ZV

 

[jlee]

Some cars require that the ABS servos be cycled. This can sometimes require special tools.

For the OP: The car is not safe to drive at this point and under no circumstances should you take the car onto public roads. Until you have found and repaired the leak and bled the brake system, the car should be parked and not used. IT IS UNSAFE.

If you do not have the tools to repair the car yourself, it should be TOWED to a repair shop where the brakes can be brought back into safe operation.

Again, DO NOT DRIVE THE CAR UNTIL THE BRAKES ARE REPAIRED AND FULLY OPERATIONAL. You want to play with your own life, that's fine, but if you're taking the car out on public roads you're putting other people in danger.

ZV

It doesn't appear that his car needs any special attention - link

 

[Zenmervolt]

It doesn't appear that his car needs any special attention - link

Yup, looks like the procedure is to bleed the brakes normally, then drive and brake hard enough for ABS to activate, then bleed the brakes again. I should've looked that up first. 🙂

ZV

 

[krnmastersgt]

I had no intention of using the car as if nothing was wrong with it and I apologize if that's how my post came off. I meant testing it around 10-11 PM in the quiet streets around here to see how the brakes were reacting.

On that note I poured in some more fluid as once I opened it up the reservoir was just a tad under the MIN line to make sure it's just a brake fluid issue overall with the car. After pumping the crap out of it and driving around in circles for a while the brakes have firmed up to what they were prior to this little incident. Going to repeat this for another day or two and see how the fluid level is holding (if there's a leak I might take the car in for a pretty decent service: replace pads, flush transmission, etc.).

Again thanks for the input and the words of warning. I do know this system needs to be fully flushed if nothing else though since as I added in the new batch of fluid, it stirred around a bit of the old one and there seems to be a decent amount of sediment in the system. Not sure where it's getting in but hopefully it's just from a worn out pad on one of the tires or something.

 

[DaTT]

I find the most common place for a fluid leak is on the wheel cylinder on the back drum brakes (providing its not 4 wheel disc). It's not the only place to spring a leak, but in my experience, it's the most common.

 

[sontakke]

Assuming you have rear drum brakes, put it in the reverse and repeatedly do hard stops. If the rears are working even slightly and if your adjuster is not frozen, this will automatically adjust your rear brakes and will make your pedal feel firmer and your vehicle will stop better.

But if the rears are completely out of adjustment or if the mechanism is frozen, then you need to take the drum off to readjust them or you can use the two screw driver technique from the back of the drum but trust me, not every technician will know how to do that without taking the drum off.

 

[BUTCH1]

I had no intention of using the car as if nothing was wrong with it and I apologize if that's how my post came off. I meant testing it around 10-11 PM in the quiet streets around here to see how the brakes were reacting.

On that note I poured in some more fluid as once I opened it up the reservoir was just a tad under the MIN line to make sure it's just a brake fluid issue overall with the car. After pumping the crap out of it and driving around in circles for a while the brakes have firmed up to what they were prior to this little incident. Going to repeat this for another day or two and see how the fluid level is holding (if there's a leak I might take the car in for a pretty decent service: replace pads, flush transmission, etc.).

Again thanks for the input and the words of warning. I do know this system needs to be fully flushed if nothing else though since as I added in the new batch of fluid, it stirred around a bit of the old one and there seems to be a decent amount of sediment in the system. Not sure where it's getting in but hopefully it's just from a worn out pad on one of the tires or something.

It's always a good idea IMO to draw off all the old fluid in the MC before adding more or when flushing, just use a turkey baster or a medi-sryinge. Pad wear will not be an issue with fluid quality, it's nasty because it was never changed during a routine pad replacement, get it out of there as in addition to sediment there might be a fair amount of moisture present as well, promoting internal caliper rusting..

 

[KCfromNC]

You were given a lot of good advice, but you don't seem to be taking it.

You are losing fluid, this needs to be fixed. Once fixed the system WILL need to be bled. Doing so as soon as possible is the best advice.

Brake fluid also goes down as you use up brake pads. Something has to fill the extra space to compress the slimmer pads down to hit the rotors, and that's extra fluid in this case. Not that it couldn't be another problem entirely, but rule out the obvious cause first - which in this case means checking that "normal" metal on metal grinding sound :/

 

[Zenmervolt]

Brake fluid also goes down as you use up brake pads. Something has to fill the extra space to compress the slimmer pads down to hit the rotors, and that's extra fluid in this case. Not that it couldn't be another problem entirely, but rule out the obvious cause first - which in this case means checking that "normal" metal on metal grinding sound :/

I've yet to see a car where the brake fluid would be so low as to cause the master cylinder to suck air just from worn pads.

ZV

 

[thomsbrain]

Did the 90 Accord even have ABS? I thought they introduced that in a later mid-gen refresh. My 91 didn't have it.

 

[NutBucket]

In 91 the SE had it. Definitely not common.

 

[KCfromNC]

I've yet to see a car where the brake fluid would be so low as to cause the master cylinder to suck air just from worn pads.

It does it in both of my track cars (stock brake system aside from pad compound). Not sure if track use changes the equation or just accelerates the process so I see used up pads and rotors more frequently than most.

But mainly I was just reminding the OP not to ignore the grinding sound.

 

[Zenmervolt]

It does it in both of my track cars (stock brake system aside from pad compound). Not sure if track use changes the equation or just accelerates the process so I see used up pads and rotors more frequently than most.

Might also be the cornering forces causing the fluid to shift in the reservoir. I've not seen it in a street car, but I also tend to be meticulous about the wear limits on both pads and rotors. The engineers aren't going to design something that's sucking air until both pads and rotors are beyond the minimum thickness.

But mainly I was just reminding the OP not to ignore the grinding sound.

Valid. Especially if he's thrown a pad.

ZV