Jerking brakes My car jerks when u step on the break not all the time sometimes it doesn't and it feels so bumpy on the road and shaky not the steering wheel it's the seat and it's only 90,000 miles in it , is it the transmission problem please help me ..

Only when braking.

Can you feel some hard jerking passing on bumpy road? Have the suspension checked.

Examine your engine mounts and the 'dogbone' at the top right of the engine. The jerking symptoms you describe do sound like a failed mount. The front lower mount is a hydraulic cushion type, and the chief sign of failure is oil leakage from it.

As to the wobbliness and bumpy ride, that sounds like the front suspension struts need replacement. You need good quality spring compressors to try that job yourself.

It is a crude test, but if you can easily bounce the front corners of the car up and down, and it keeps bouncing when you let go, then the struts are worn out.

Front brake rotors need to be turned and new pads. Adjust rear brakes. the front brakes are doing all of the stopping. (overheating the rotors, premature pad wear).

mine gets like that when its low on fluid

the jerking may be due to uneven braking on either side of the car it may be that a piston is stuck. need to take car off the road remove tyres then brakecalipers a good indication that a piston is stuck is when you disconnect the brake lines and pull pads/caliper of the rotor the piston will be extremely hard to move

it cound be a sigh off a head gasket starting to go have to do a pressure test hope not

Mine was a crank shaft sensor located by the distributor.If u have a parts house that run free diagnostics it can tell u.

if the pedal jerks when you are applying the brakes, then the rotors are probably out of round

it sounds like it may be out of time and in the case you need to replace timing belt and pulleys and get retimed