Brake master questions and tips
#1
Honda-Tech Member
Thread Starter
Brake master questions and tips
Hey guys, I'll be replacing my brake master cylinder soon.
I recently replaced my rear brakes (pushed the piston in properly, loosened the valve) and have a few questions. Im replacing it because I have a spongy pedal and its been like this for over a year.
1. The pedal gets spongy only after diving for a while (heated fluid)
2. On hot days its really really bad, especially while idling on an uphill
3. When the car is at Op Temp, and if I slam on the brake, the idle will rise. Something to do with my prop valve or booster?
4. If it is my prop valve or booster, could this be the reason my pedal is spongy? I already bled all the brakes in the proper sequence and no luck.
5. When I replaced my rear brakes, I heard dragging from the pads/rotor. Even with the wheel jacked I could rotate it effortlessly but there was still dragging. How do I adjust this? Is this the booster adjustment?
6. Should I empty all the fluid out of all the lines, bench bleed the new MC, then bleed each caliper one by one RR FL RL FR?
Thanks!
I recently replaced my rear brakes (pushed the piston in properly, loosened the valve) and have a few questions. Im replacing it because I have a spongy pedal and its been like this for over a year.
1. The pedal gets spongy only after diving for a while (heated fluid)
2. On hot days its really really bad, especially while idling on an uphill
3. When the car is at Op Temp, and if I slam on the brake, the idle will rise. Something to do with my prop valve or booster?
4. If it is my prop valve or booster, could this be the reason my pedal is spongy? I already bled all the brakes in the proper sequence and no luck.
5. When I replaced my rear brakes, I heard dragging from the pads/rotor. Even with the wheel jacked I could rotate it effortlessly but there was still dragging. How do I adjust this? Is this the booster adjustment?
6. Should I empty all the fluid out of all the lines, bench bleed the new MC, then bleed each caliper one by one RR FL RL FR?
Thanks!
#2
Re: Brake master questions and tips
#3 makes me think that the booster is leaking air - and speeding the idle by allowing more into the intake.
It's wise to fix the things you know aren't right first (just like dealing with codes) before spending time and money trying to find other things. Often, when you fix the known problem others disappear as well - and save you a lot of grief.
Anyone else find the 'stomp on brake to raise idle' a bit suspicious?
Mark
It's wise to fix the things you know aren't right first (just like dealing with codes) before spending time and money trying to find other things. Often, when you fix the known problem others disappear as well - and save you a lot of grief.
Anyone else find the 'stomp on brake to raise idle' a bit suspicious?
Mark
#3
Honda-Tech Member
Join Date: Apr 2011
Location: Near Pacific Coast Highway
Posts: 1,197
Likes: 0
Received 0 Likes
on
0 Posts
Re: Brake master questions and tips
mines doing the same thing sinking pedal and when i hit brakes idle comes up!
i dont wana jump at the master cylinder just yet!
IM IN FOR THE RESULTS
i dont wana jump at the master cylinder just yet!
IM IN FOR THE RESULTS
#4
Honda-Tech Member
Thread Starter
Re: Brake master questions and tips
Okay honda tech, I'll look around my booster. I can disconnect the MC from the boosted without fluid going anywhere correct? I'll look around and check my tolerances. Also any tips on how to check for thisstuff?
Is the booster just supposed to keep a vacuum? There is no fluid inside right? Between the master cylinder and firewall, I have no idea what goes on in there lol
Is the booster just supposed to keep a vacuum? There is no fluid inside right? Between the master cylinder and firewall, I have no idea what goes on in there lol
#5
Re: Brake master questions and tips
Is the booster just supposed to keep a vacuum? There is no fluid inside right? Between the master cylinder and firewall, I have no idea what goes on in there lol
As for your spongy pedal, that's normally due to any of these things:
1) seized moving-parts at/in the caliper
2) air in the lines
3) hoses expanding with pressure
4) aftermarket pads
5) rust on the caliper/pad parts
6) aftermarket MC seals too soft
It takes skill and experience to do brakes properly; there's more involved than just swapping parts.
I have a page on replacing the Master Cylinder, if you'd like to look through that:
http://www.tegger.com/hondafaq/maste...ace/index.html
This is a 2nd Gen Integra, of course.
By the way, DO NOT drain the lines of fluid!!!!!! You will cause yourself tons of extra work by introducing enormous amounts of air into the system.
#7
Honda-Tech Member
Thread Starter
Re: Brake master questions and tips
Read the service manual, and this is what it said:
BRAKE BOOSTER INSPECTION
Functional test:
1. With the engine stopped, Depress the brake pedal several times, then depress the pedal hard and hold that pressure for 15 seconds. If the pedal sinks, the master cylinder, brake line or a brake caliper is faulty
2. Start the engine with the pedal depressed. If the pedal sinks slightly, the vacuum booster is working. If the pedal height does not vary, the booster or the check valve is faulty
Leak Test:
1. Depress the brake pedal with the engine running then stop the engine. If the pedal height does not vary while depressed for 30 seconds, the vacuum booster is OK. If the pedal rises, the booster is faulty
2. With the engine stopped, depress the brake pedal several times using normal pressure. When the pedal is first depressed, it should be low. On consecutive applications, the pedal height should gradually rise. If the pedal position does not vary, check the booster check valve.
Check valve test:
1. Disconnect the brake booster vacuum hose at the booster.
2. Start the engine and let it idle. There should be a vacuum available. If no vacuum is available, the check valve is not working correctly. Replace the check valve and retest.
END TEST
I'm going to go outside and try this right now lol. Hope this helps anyone
BRAKE BOOSTER INSPECTION
Functional test:
1. With the engine stopped, Depress the brake pedal several times, then depress the pedal hard and hold that pressure for 15 seconds. If the pedal sinks, the master cylinder, brake line or a brake caliper is faulty
2. Start the engine with the pedal depressed. If the pedal sinks slightly, the vacuum booster is working. If the pedal height does not vary, the booster or the check valve is faulty
Leak Test:
1. Depress the brake pedal with the engine running then stop the engine. If the pedal height does not vary while depressed for 30 seconds, the vacuum booster is OK. If the pedal rises, the booster is faulty
2. With the engine stopped, depress the brake pedal several times using normal pressure. When the pedal is first depressed, it should be low. On consecutive applications, the pedal height should gradually rise. If the pedal position does not vary, check the booster check valve.
Check valve test:
1. Disconnect the brake booster vacuum hose at the booster.
2. Start the engine and let it idle. There should be a vacuum available. If no vacuum is available, the check valve is not working correctly. Replace the check valve and retest.
END TEST
I'm going to go outside and try this right now lol. Hope this helps anyone
Thread
Thread Starter
Forum
Replies
Last Post
HairyHarry
Honda Civic / Del Sol (1992 - 2000)
23
10-08-2015 03:17 PM
douglaslovin
Honda CRX / EF Civic (1988 - 1991)
3
11-26-2009 11:41 AM