2001 Acura TL Q&A

2001 Acura TL Question: The brake pedal goes to the floor with constant pressure when stopped.

The car was just in for repair for this issue. New front brakes and a master cylinder were installed. The pedal still goes to the floor. The mechanic says it is normal. Is this normal? It does not seem right to me. Thanks -
Answer 1
If it goes to the floor, it is not normal. Does it do it with the engine off. -
Comment 1
I just checked. The pedal holds firm with the engine off. -
Comment 2
Replace the brake booster. Just something I learned over the years. -
Comment 3
Wow. You are smarter than all of the mechanics at the Acura of Lynnwood dealership(just north of Seattle). They have misdiagnosed this problem 3 times over 2 years. Was the master cylinder replaced for no reason? Thank You -
Comment 4
If the pedal drops with the engine off and running it is usually the master cylinder with no air in system and no leaks. If it holds with engine off and drops with the engine running I have changed the booster and it has worked for years. Trial and error from 20 years ago. Others will argue the point but after they have tried it they believe as well. -
Answer 2
Another direction for you is to suggest to your mechanic to try a (little known) flex hose block off test...that will find this problem in about 5 minuets, or less!! If after hoses are blocked (pinched) the pedal is now high and firm,,forget about the master cylinder altogether...problem is air in system or cailper/brake pad not applying correctly. This will test 'REAR' brake componets as well...which are way too often overlooked! It works every time!! Learned this in a brake system failure diagnoses seminar years ago......test with engine running!!.... Testing the system is the key here!!! ...No it is NOT normal for the pedal to go to the floor! Rear calipers may be stuck on mounting bolts!!! -
Comment 1
Thank You. Very interesting. I never knew brakes could be so complex to troubleshoot. -
Comment 2
That's just a start... 'Much more' to it than that.... You're welcom.....Let us and other owners know what you find out... -