96 Toyoto Corolla brake problem

[fishhead]

Last night while I was driving in town I noticed that my brake pedal was getting hard to push and it seemed like my brakes were slightly dragging. I made my final stop at the store before heading home and when I got back in the brakes were fine.

This morning I made a short trip with several brakings and it was fine. Then I drove more than 100 miles and let the car sit for several hours. The brakes seemed fine. On the return trip I drove about 20 miles after leaving the city and when I went to stop at an intersection I couldn't depress the pedal enough to trip the cruise control off. Again it seemed like the brakes were slightly dragging. I stopped in a parking lot and turned it off while I went into the store. When I came out the pedal was still high and tight but when I started the car the pedal went down almost to normal.

The brake light that comes on when I start the car did not come on either time.

Last spring/summer I had brain fade and put some power steering fluid in the brake reservoir but it was at least several months ago.

Any ideas other than flushing the reservoir and all the brake lines with fresh brake fluid?

[blufford]

I think a good flushing might help out. Someone with more experience on this forum might be ble to tell you if you may have damaged your brake seals or liner. Even though they make the containers of brake and power steering fluid different its easy to get confused and switch them especially at night.

[fishhead]

Oh no I did this in broad daylight. It made perfect sense at the time too.

I don't understand why my brake pedal would get stiff when I was driving down the highway and not using the brake unless there is some kind of engine assist that could have built up pressure.

[blufford]

I had an old 1973 Mercedes 220 D that would do that but it had a hole in its brake line. See any leaks?

[agmantoo]

Fishhead,
I got this off the internet, hope it helps.
The most common cause of brake fluid contamination next to water in the system is incorrect fluid type added to the system. The obvious tell tale sign is a swollen rubber seal for the brake master cylinder. Power steering fluid added mistakenly to the brake master cylinder fluid is usually the culprit. The packaging of power steering fluid and brake fluid are nearly identical, same color labels and many times the bottles are the same shape. This makes it very easy to add the wrong fluid. Once the brake system has been contaminated by power steering fluid it can distort all the rubber components within the master cylinder, ABS units, brake hoses, proportioning valves, calipers and wheel cylinders. Bleeding the brakes is not the answer in this case, the only sure way to correctly repair a system that has been contaminated in this manner is to replace all the parts that have rubber components.

[blufford]

Fishhead, I would hope that just the fluid failed if you don't see any leaks and try bleeding them and adding new fluid. I would at least do that. If that didn't do it you may have a bigger problem such as Agmantoo has posted. Even if it works, you may still have a bigger problem down the road.

[fishhead]

Originally Posted by agmantoo

Fishhead,
I got this off the internet, hope it helps.
The most common cause of brake fluid contamination next to water in the system is incorrect fluid type added to the system. The obvious tell tale sign is a swollen rubber seal for the brake master cylinder. Power steering fluid added mistakenly to the brake master cylinder fluid is usually the culprit. The packaging of power steering fluid and brake fluid are nearly identical, same color labels and many times the bottles are the same shape. This makes it very easy to add the wrong fluid. Once the brake system has been contaminated by power steering fluid it can distort all the rubber components within the master cylinder, ABS units, brake hoses, proportioning valves, calipers and wheel cylinders. Bleeding the brakes is not the answer in this case, the only sure way to correctly repair a system that has been contaminated in this manner is to replace all the parts that have rubber components.

OUCH!$$$$$$

Oh well whatever it takes. I'm calling the mechanic first thing in the morning to get it in to see what he can do. Whatever is going to happen is going to happen. I must have too much money in my wallet again.

Hopefully it's something minor like a leaky line.

[ninny]

You might check your power brake booster. If it has a vacuum leak it will make your brakes hard to push. If you do decide that you need to replace the components in your brake system, you can buy rebuild kits for your master cylinder and your wheel cylinders. If you're mechanically adept at all, you can repair these yourself. You'll need a drill and a hone for the cylinders but those don't cost that much. This isn't a hard job and will definitely be cheaper than taking it to a mechanic.


.

[fishhead]

Originally Posted by ninny

You might check your power brake booster. If it has a vacuum leak it will make your brakes hard to push. If you do decide that you need to replace the components in your brake system, you can buy rebuild kits for your master cylinder and your wheel cylinders. If you're mechanically adept at all, you can repair these yourself. You'll need a drill and a hone for the cylinders but those don't cost that much. This isn't a hard job and will definitely be cheaper than taking it to a mechanic.


.

Would the vaccum leak be intermittant? Yesterday when I came up to the intersection I couldn't push the pedal far enough to disengage the cruise control. Then I shut the motor off and restarted it maybe 10 minutes later. The pedal dropped as the motor started. It acted normally the rest of the trip home.

I do some mechanical things but this one I'll take it to the shop so that I know it's done right plus we are supposed to be in for a serious drop in temperature this week.

[ninny]

Originally Posted by fishhead

Would the vaccum leak be intermittant? Yesterday when I came up to the intersection I couldn't push the pedal far enough to disengage the cruise control. Then I shut the motor off and restarted it maybe 10 minutes later. The pedal dropped as the motor started. It acted normally the rest of the trip home.

I do some mechanical things but this one I'll take it to the shop so that I know it's done right plus we are supposed to be in for a serious drop in temperature this week.

It is odd that the problem is intermittent but it's possible. When you're driving at highway speed, you're creating more vacuum, thus your vacuum booster would work better if the leak on the booster were small. When you're driving in town, less vacuum so your brakes would be harder to press in. Check for a vacuum leak on your hose going to the vacuum booster and any mechanic shop can do a vacuum check on the booster.

If you opt not to rebuild the wheel cylinders and master cylinder yourself, you can always replace them yourself if you feel comfortable with this. Most of this is just taking a couple of bolts loose and replacing the part, bleeding the brakes and that should take care of the replacement issue.

Labor is going to eat your lunch if you take it to a mechanic shop unless, that is, you happen to be friends with a mechanic that will do it on the cheap. Down here mechanics are charging around $75 an hour for shop time plus parts.

.

[fishhead]

At 60 mph the pedal was too stiff to disengage the cruise control so that doesn't sound like a vaccum leak.

I've got it scheduled for the shop in the morning. He's looking for a master cylinder just in case. Hopefully that is all the damage that I did.

Adding power steering fluid to the brake reservoir made perfect sense at the time. I hate it when that happens. Too many things on my mind I guess.

[ninny]

Originally Posted by fishhead

At 60 mph the pedal was too stiff to disengage the cruise control so that doesn't sound like a vaccum leak.

I've got it scheduled for the shop in the morning. He's looking for a master cylinder just in case. Hopefully that is all the damage that I did.

Adding power steering fluid to the brake reservoir made perfect sense at the time. I hate it when that happens. Too many things on my mind I guess.

Don't feel bad, we've all done stuff like that at some time or other. Just consider it one of life's experiences, although it might be a little expensive. Hope you get it fixed up okay without too much cost.

.

[fishhead]

Thanks. It's in the shop right now.

[fishhead]

$185 total for a new master cylinder installed. That's quite a bit for a momentary brain fade but I had prepared myself for much much worse.