If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
Did a brake flush damage my master cylinder?
I recently had the brake fluid flushed on my '95 Honda Civic (80k
miles). A week later I noticed my brake pedal would slowly sink to the floor while I was waiting at red lights. I took the car back to the service center (part of a large national chain), and they correctly determined that the master cylinder was the culprit. They denied, however, that the brake flush had anything to do with the master cylinder failure. (To hear the office manager tell it, you would think the master cylinder was totally unrelated to the brakes.) Now I'm not a mechanic, but I'm having a hard time believing that the master cylinder just happened to give out when it did. Earlier today I read that the seals on the master cylinder can be damaged if the mechanic drains the brake fluid by depressing the brake pedal all the way to the floor, and that a professional shop should use other equipment to get the job done. Am I wrong for assuming the mechanic took some shortcut (or just didn't know better) and ended up damaging the master cylinder? Or is this the kind of thing where, even if done correctly, the master cylinder still can get damaged? (I did read a comment that it's not uncommon to have to replace the master cylinder after having your brakes worked on.) The new master cylinder cost $260. If the mechanic was negligent, I don't want to have to pay for it. If, however, it's just part of owning a ten year old car, I'll suck it up. What do you think? - Kevin |
#2
|
|||
|
|||
) scribbled:
> Am I wrong for assuming the mechanic took some shortcut (or just didn't > know better) and ended up damaging the master cylinder? Probable. > Or is this the kind of thing where, even if done correctly, the master > cylinder still can get damaged? > (I did read a comment that it's not uncommon to have to replace the > master cylinder after having your brakes worked on.) Happened to me recently. Replaced *ALL* calipers with new ones, new rotors all the way around, new pads, new lines. Bled the brakes - never could get a solid pedal. Turned out, once I replaced the master, all was fine. And there wasnt anything wrong with the system in the first place - I had a nice solid pedal. It was time to do a brake job anyway, and I figured with 190k miles, I might as well redo the whole system (sans the master). -- remove MYSHOES to email |
#3
|
|||
|
|||
>
> Earlier today I read that the seals on the master cylinder can be > damaged if the mechanic drains the brake fluid by depressing the brake > pedal all the way to the floor, and that a professional shop should use > other equipment to get the job done. Nope, not true. Mechanics have bled brakes for decades by applying pressure, loosening the cocks, and allowing bubbles and old brake fluid to exit. You dont have to use fancy equipment, although it makes the job faster, though not necessarily better. Doesnt hurt anything. |
#4
|
|||
|
|||
> wrote in message . .. > > > > Earlier today I read that the seals on the master cylinder can be > > damaged if the mechanic drains the brake fluid by depressing the brake > > pedal all the way to the floor, and that a professional shop should use > > other equipment to get the job done. > > > Nope, not true. Mechanics have bled brakes for decades by applying > pressure, > loosening the cocks, and allowing bubbles and old brake fluid to exit. > > You dont have to use fancy equipment, although it makes the job faster, > though > not necessarily better. Doesnt hurt anything. > > |
#5
|
|||
|
|||
> wrote in message . .. > > > > Earlier today I read that the seals on the master cylinder can be > > damaged if the mechanic drains the brake fluid by depressing the brake > > pedal all the way to the floor, and that a professional shop should use > > other equipment to get the job done. > > > Nope, not true. Mechanics have bled brakes for decades by applying > pressure, > loosening the cocks, and allowing bubbles and old brake fluid to exit. > > You dont have to use fancy equipment, although it makes the job faster, > though > not necessarily better. Doesnt hurt anything. Ive seen this done, and done it myself for years, but have never damaged a master cylinder. Still, the logic is there that it could happen, and I have to retract my statement above. Just because I always got away with it doesnt mean it doesnt happen. |
#6
|
|||
|
|||
|
#7
|
|||
|
|||
"N8N" > wrote in message oups.com... > My experiences are exactly opposite, I've only done brake work on > exactly one car over the years where I a) didn't replace the master > cylinder up front and b) didn't end up replacing the master cylinder > after it failed shortly thereafter. Of course, Murphy is always > hanging out with me... > > nate We went through a spell a good number of years ago where master cylinders went pretty fast on their own. Maybe Chryslers were worst, but either the metallurgy was bad or the fluid had a glitch. These could not be successfully rebuilt either, since the pitting, leakage potential was so bad. This was a case where OEM was terrible, but some aftermarket parts (EIS, among others) worked out okay. Basically, if you ruin a master cylinder by bleeding using it, I wonder how much time you had anyway. A lot of people dont realize that brake fluid can oxidize and become acidic, and that when water gets into it, corrosion is likely to follow. When you get that first deposit of corrosion byproduct on the metal, you have created a corrosion cell that can accelerate matters. The wise bird flushes out the brake fluid every few years, but not many of us do that. In fact, I am sitting here knowing that I should have flushed my Teves system before now, and am not relishing doing it. Replacing that sucker costs about ten times more than a Honda master cylinder. |
#8
|
|||
|
|||
|
#10
|
|||
|
|||
In article >, says...
> > >On 6 Jul 2005 16:39:50 -0700, wrote: > >>> >>Now I'm not a mechanic, but I'm having a hard time believing that the >>master cylinder just happened to give out when it did. > > >You would most likely be correct. The master cylinder tends to get >rust and gunk in the bore because you only push the pedal so far down. >When the brakes are bled if you push the pedal to the floor then the >seals in the master cylinder get torn up by the rough surface. Once >the seals are damaged fluid leaks by them internally in the master >cylinder causing your pedal to drop. This is one reason why you want to change your brake fluid regularly. So that you don't get this crud accumulating in the MC and so that the water that mixes with your brake fluid doesn't rust out the brake system. ---------------- Alex |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
help abs brake pump why would brake fluid come out of the master cylinder when ( top ) when brakes are applied when rotters are hot master cylinder has been changed system has been bled 2nd help should pump motor make a sound when ke | envirokid | Ford Explorer | 0 | April 8th 05 09:10 PM |
Brake Master Cylinder Flush | Marcy | Technology | 9 | January 26th 05 09:49 PM |
Brake rotors already grooving | [email protected] | Technology | 46 | January 15th 05 03:42 PM |
dual ci6rcuit master brake cylinder | JS | VW air cooled | 3 | December 20th 04 02:42 PM |
'97 Voyager - Brakes | MamaB | Dodge | 20 | December 6th 04 12:26 AM |