This is the master cylinder right?

I got my brother in laws 2004 tacoma sr5 4x4 yesterday, the brakes are pretty weak, they will stop it, but you have to pump them to get it to stop. When the vehicle is off, and you pump the brake, the first time it goes a bit lower then the 2nd, after that all of the pumps are pretty much the same, and each time you can feel it stop

When you start the engine with your foot still on the pedal, it sinks some right off the bat, and then continues to sink, if you pump it, it firms back up, but always continues to sink, even if you left it running without pumping the brake while you tested the lights and speakers while listening to thunderstruck. Then tested the brakes again, and they were the same as they were, pumping causes them to firm up but the peddle always continues to sink.

I have checked under it for leaks and found none, no drips on the driveway, no dampness around any line, caliper or the drums nothing like that, no leaks around the master or booster under the hood, i know the tacoma has another part of the brake system somewhere in the rear, but i do not know where that is so i was unable to check it.

Also
The parking brake does not seem to engage, i checked under the dash and it does appear that the cable moves, not sure if the lever is supposed to get tension on it when you pull it, but from start to as far out as it will go, it feels the same, and all the way out, the truck will roll by hand. I am pretty sure that this part has nothing to do with the master cylinder, but any advice would be welcome as to where to start looking, im going to change all of the brakes out this weekend, rotors, pads, drums and shoes, so i will be right down where i need to be to fix anything if it can be fixed.

Worth mentioning that it also has surface rust under it that is flaky, but, doesn't appear to go through anywhere, i banged on it with a hammer from one end to the other and it was solid, no parts where the hammer went through or banging on the frame caused a area to open up, about all that happened was a rain of flakes, going to pressure wash under it this weekend when i have the wheels off, and wire brush it anything that doesnt clean up, i have a rust coating treatment in mind to order once i have it cleaned up a bit and make 100% sure nothing hidden comes up. so it is very possible something related to the parking brake has rusted up, the truck hasnt been driven in several years. so this weekend it is getting the treatment, all new fluids, new brakes (they are in need of changing) and a good cleaning top to bottom, it has a layer of dust so think that it changed the color of its black to a greenish yellow

 

yep, definitely sounds like the master cylinder is shot.

the pedal will drop once you add engine vacuum but then will hold.

the parking brake is manual cables so look under the truck and check the cable system to see whats moving and what isn't. there is a yoke that splits the xcable into two for each side and this parts often gets rusty and has issues but you might also have a broken or disconnected cable

 

Thanks, that is what i thought, but it is always nice to get a 2nd opinion prior to buying the part, cause i might have been reading it wrong and it be the booster instead.

I do have one other question, the parts store said that they have it with and without stability control, i didnt see anything anywhere on my tacoma that indicated that it had stability control so i opted to order the one that didnt have it, mainly because it was the only one they could get.

My question is, what is the difference and how can you tell?

 

I think that's what they call the VSC but I don't know for sure

 

It does not sound like the master cylinder to me. It sounds like air in the line. You can not pump up a master cylinder and get good brakes - it just continues to leak by. You can pump up and compress air in the lines and get your brakes by. Before you replace the master cylinder bleed the brakes. You can do that for the cost of a can of brake fluid.

The e-brake not working - the handle in the cab is attached to a cable. The cable goes through the floor of the truck near the accelerator pedal. From there it leads under the truck beneath the floor pan to a spring loaded lever. This is (if my memory is right) right about the back of the door. There it attaches to a spring loaded lever and another cable. Follow all the cables and look for a break.

 

One thing that keeps coming to my mind about your e-brake is the adjustment of the drum brakes. I had never adjusted mine the entire time ive owned it, and my brake handle came most of the way out to get it to work. Finally adjusted it, and sure as hell just like new, a few clicks and its set. Something to think about... Look up fsm 2003 tacoma. Its a pdf for the factory service manual. Loads of info. I know its 03 but lots of the parts are still the same. Also, if your pocket book is deep, google and read up on tacoma tundra brake swap.. I fully intend to do the swap in a couple months. Like mentioned before, bleed your brake lines. Its cheaper and not hard. You can do it alone too. Its not a bad thing to just go ahead and flush the whole system and put new fluid In. If you are a rookie, dont let the pedal hit the floor when you're pumping the master cylinder. Also there is a brake proportioning valve on the rear driver side frame. Easily accessible if you remove the spare. I bled mine in the order of proportion valve, pass rear, driver rear, pass front, driver front. Hope all this helps.. Good luck, and we want pictures!

 

Found the ebrake problem, the cable was broken almost right at the first arm under the cab, thankfully it was on the side that goes to the lever, and everything on the other side moves correctly when i moved the lever.

I'll try bleeding the brakes before the MC

Thanks

 

Just because you dont see any visible leaks does not necessarily mean that thry are not there. Pull the wheels off. Inspect the lines, calipers, pads while you are there. Remove the drums and inspect the wheel cylinders. Grab the rubber boots and pinch them. Make sure there isn't any fluid leaking out of them. If your shoes are contaminated, replace as needed. They are shot if they are. If all appears dry front to back move onto to bleeding the brakes. No sense in bleeding them if the brake system is leaking. Brake portioning valve is related to ABS and should be irrelevant. Should. If all checks out well condemn the master cylinder.

 

I think your wrong about the valve. Its actually a load sensing deal. When there is enough of a load in the bed it gets triggered. I do believe it IS RELEVANT and should be bled. Not trying to start an argument, but merely pass the correct info. Besides, i bled mine and it took all of five seconds. OP if you want more info just google "04 Tacoma load proportioning valve" or something similar. OP, i did a bit of searching for you. This link is fora lifted tacoma, but explains the load sensing proportioning valve...https://www.tacomaworld.com/threads/do-i-need-a-brake-proportion-valve-whats-it-for.154551/

 

thanks for the info everyone, also not trying to start a argument, more so as i was the one who asked for the help, but i tend toward agreeing with roehoe72, if it has a bleed valve to me at least, that means that someone somewhere intended for it to be used, so i will add it to the list of areas to bleed.

 

Bleed brakes and adjust rear drum brakes wouldn't hurt to pull drums and check self adjusters and overall condition [brake shoes and hardware are not that expensive].

 

Your ebrake is what keeps your rear brakes in adjustment. Since this truck is new to you and it sounds like it wasn't properly maintained I would inspect everything.

Change all fluids, front rear diff, tcase, trans, oil, brake and power steering.

Since the rear brake hasn't been used go ahead and get a hardware kit, shoes and possibly drums. Be sure to inspect your wheel cylinders, axle seals and leaf spring bushings while your in there. Sometimes older wheel cylinders wheel leek if over extended or once pushed back in.

Inspect everything on the front when you have the wheels off.. It's best to use a long pry bar to check your upper lower ball joints, upper lower control arm bushing, steering rack pushing and front diff bushings. Be sure to check the 4 bolts that hold your spindle to the lower ball joint, back them out one at a time and put red lock tight on them..

By doing this you will find out a lot about your new truck. Even if you can't afford to fix everything at least you know its limitations. This is of course if you deem it safe enough to drive.