Brake question (non lexus).
01-02-06, 01:02 PM
#1
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Brake question (non lexus).
I've got a strange problem with a 95 Mitsubishi Montero truck.
The brakes worked fine till one day when the brake pedal decided to become really spongy and also engages very low (close to the firewall).
After checking all the calipers and pads (they're new), bleeding the system, I decided it was a bad master cylinder.
Changed the master cylinder. no effect. Could've been a bad new M/C so I chaned it yet again. no change.
With engine off, the pedal is solid / hard and doesnt drop at all even after constant pressure. Hence I'm assuming there's no air in the system and M/C is good.
As soon as the engine is turned on, the pedal drops almost 5 or so inches. With the engine ON and car running I can get a high pedal if the pedal is pumped. Given I've bled the system thoroughly atleast 8 times by now, bench bled master cylinder as well, could someone kindly tell me what else could be causing this issue ? It does have ABS but the ABS isnt working due to bad ABS sensors. The brakes worked fine for a year even after ABS wasn't working so I'm assuming ABS is not related to this issue... any suggestions would be appreciated.
The brakes worked fine till one day when the brake pedal decided to become really spongy and also engages very low (close to the firewall).
After checking all the calipers and pads (they're new), bleeding the system, I decided it was a bad master cylinder.
Changed the master cylinder. no effect. Could've been a bad new M/C so I chaned it yet again. no change.
With engine off, the pedal is solid / hard and doesnt drop at all even after constant pressure. Hence I'm assuming there's no air in the system and M/C is good.
As soon as the engine is turned on, the pedal drops almost 5 or so inches. With the engine ON and car running I can get a high pedal if the pedal is pumped. Given I've bled the system thoroughly atleast 8 times by now, bench bled master cylinder as well, could someone kindly tell me what else could be causing this issue ? It does have ABS but the ABS isnt working due to bad ABS sensors. The brakes worked fine for a year even after ABS wasn't working so I'm assuming ABS is not related to this issue... any suggestions would be appreciated.
01-02-06, 04:30 PM
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Originally Posted by Lexs400
I've got a strange problem with a 95 Mitsubishi Montero truck.
The brakes worked fine till one day when the brake pedal decided to become really spongy and also engages very low (close to the firewall).
After checking all the calipers and pads (they're new), bleeding the system, I decided it was a bad master cylinder.
Changed the master cylinder. no effect. Could've been a bad new M/C so I chaned it yet again. no change.
With engine off, the pedal is solid / hard and doesnt drop at all even after constant pressure. Hence I'm assuming there's no air in the system and M/C is good.
As soon as the engine is turned on, the pedal drops almost 5 or so inches. With the engine ON and car running I can get a high pedal if the pedal is pumped. Given I've bled the system thoroughly atleast 8 times by now, bench bled master cylinder as well, could someone kindly tell me what else could be causing this issue ? It does have ABS but the ABS isnt working due to bad ABS sensors. The brakes worked fine for a year even after ABS wasn't working so I'm assuming ABS is not related to this issue... any suggestions would be appreciated.
The brakes worked fine till one day when the brake pedal decided to become really spongy and also engages very low (close to the firewall).
After checking all the calipers and pads (they're new), bleeding the system, I decided it was a bad master cylinder.
Changed the master cylinder. no effect. Could've been a bad new M/C so I chaned it yet again. no change.
With engine off, the pedal is solid / hard and doesnt drop at all even after constant pressure. Hence I'm assuming there's no air in the system and M/C is good.
As soon as the engine is turned on, the pedal drops almost 5 or so inches. With the engine ON and car running I can get a high pedal if the pedal is pumped. Given I've bled the system thoroughly atleast 8 times by now, bench bled master cylinder as well, could someone kindly tell me what else could be causing this issue ? It does have ABS but the ABS isnt working due to bad ABS sensors. The brakes worked fine for a year even after ABS wasn't working so I'm assuming ABS is not related to this issue... any suggestions would be appreciated.
with koeo
pump break pedal till its rock hard
hold pedal turn on the car on
pedal should sink to floor
test 2
with koer
hold break pedal
turn off car
does the pedal go up or down or nothing
01-02-06, 07:32 PM
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Originally Posted by Lexs400
first test, yes the pedal drops when engine starts.
second test, the pedal stays same if the engine is turned off.
second test, the pedal stays same if the engine is turned off.
u check for leaks?
have u checked for sized pistons
could u have messed up the adjustments in the new brake booster. that could cause low pedal. as for spongy. u have air in the system or ur m/c is bad
01-03-06, 11:10 AM
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Originally Posted by Lexs400
. . . the brake pedal decided to become really spongy and also engages very low (close to the firewall).
Originally Posted by Lexs400
. . . As soon as the engine is turned on, the pedal drops almost 5 or so inches.
Sorry I don't have any better ideas. This is my two cents worth.
Curt
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