Skip the auto shop - Our mechanics make house calls

Q: brake sinking but still work.

asked by on

please bare with me since my English is not quite good. when car is off brake is really firm. but when starting to drive brake lose pressure but only sometime. also lose pressure when at a hill. but will stop the truck before the brake pedal hit the floor. little bit dangerous cause it work perfect sometime and other time the brake pedal will sink and surprise me

My car has 180000 miles.
My car has a manual transmission.

Hello there, a few different faults can cause the vehicle to have poor brake performance like this. The most common causes would be the brake booster, brake master cylinder, or a brake fluid leak.

When a truck has this sort of braking issue it is recommended to not drive the vehicle, as it is unsafe until the problem is resolved. A qualified technician will be able to diagnose your brake system if you’d like to get this fixed. Once this is done, an accurate repair can then be made.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What is dtc p0705 mean

Hi there. Diagnostic trouble code P0705 indicates that the Engine Control Module (ECM) or Transmission Control Module (TCM) has received an input error from the Transmission Range Sensor (TRS). This switch is also known as a pressure switch, Park Neutral...

Q: My illuminated entry system is not working

If the interior light is not coming on at all, check for a bad fuse or bulb. It is also possible the "door open" switch has malfunctioned. Failing to invoke the illuminated entry system when approaching the vehicle could be...

Q: Car will not turn off when I let go of the switch.

Hi there. The issue could be the ignition switch having a failed contact inside the switch or the distributor timing on the engine could be off causing the engine to diesel as it is shut off (continue running without the...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.