Poppie51

I am having trouble with my toyota brakes. The vehicle sat up for years then when I got it running and ready for the road I replaces the front brake pads, both wheel calipers, rear brake shoes and all the springs, both brake cylinders and the master cylinder. I bench bleed the master cylinder before installing then bleed all four wheels and the proportioning valve but still have very little brakes even after pumping the brake pedal. Does anyone have any suggestions as to what steps to take next? ( UPDATE) I just went back out to the vehicle after being told how to bleed the master cylinder while it's still on the vehicle and while my friend pressed the brake pedal the brake booster make a "bubbley" sound. Does the booster supposed to have fluid inside or would this be my problem? To make this sound it must have flluid and air inside the booster which doesn't sound right to me. Should I replace the booster?

akwheeler

did you adjust your rear brakes? if the shoes are very close to the drums or just barely touching you must still have air in the system / your brake booster is hosed or no vacuum to it. tell us more! does your pedal go to the floor without much effect? hard pedal but not much effect? does your engine start to miss when you hit the brakes?

Poppie51

I haven't adjusted the rear brakes, I thought they would adjust themselves but that is based on another vehicle I had. It would adjust itself when backing up. The pedal goes to the floor with very little effort. Pressing the brakes doesn't seem to affect the engine. The brake booster makes a gurgling or a bubbley sound when the brake pedal is pressed so it sounds to me like my brake booster is shot but I wanted to get you guys advice before spending the money to replace it then find out I had misdiagnoised the problem.Thanks for any advice.

akwheeler

#1: it takes a lot of backing up to adjust your brakes, #2 gurgling from the brake booster is bad, likely it's full of brake fluid from the old master cylinder.
try adjusting the rear brake shoes first. If your pedal goes to the floor easily after that you have air in the lines, but right now your master cylinder has to move a lot of fluid before the shoes contact the drums.

thook

if the adjusting mechanisms for the rear brakes are working correctly....and, they should be since you've replaced everything, then pulling on the parking brake multiple times is supposed to adjust the shoes. not by backing up

also, if the booster is sucking in fluid, likely it'll leak air, as well. i'd replace it. however, you should be able to easily find a used one in good shape. would save some money if found at a good price. try nix99 out of washington state

Poppie51

I have replaced the brake booster with a new booster, adjusted the rear brakes, rebled all four wheels and the proportional valve and still have very little brakes. The pedal goes down very easy and just before bottoming out the brakes engages and stops the vehicle.They work better than they did when using the old booster but still not as good as they should. I haven't checked the vacuum line going to the booster but it seems as though the booster is working because the brake pedal is so easy to press. Unless I still have air trapped in the lines somewhere, I don't know what to do. When bleeding the brakes I have the engine off and started at the rear passenger wheel then moved to the proportional valve then to the rear drivers wheel on to the front passenger wheel and finally the front drivers wheel then rebled the master cylinder again while it was still on the vehicle. Everything concerning the brakes is new except for the brake lines, rotors, brake drums and the proportioning valve.The drums and rotors look to be in good shape. Could the proportional valve be causing the problem or does anyone have any suggestions?

wyoming9

iTrader: (1)

When you pull the parking brake on how far does it come out.

Will trying to pull out with the parking Brake engaged will the vehicle stall if manual??

akwheeler

from your last post it sounds like you are finishing the bleeding process at the master cylinder by trying to bleed it last, bad move. you are likely reintroducing air if you are cracking the lines at the master cylinder. After bench bleeding you should not have to worry about the master cylinder again except to make damn sure you don't run out of fluid during the process of bleeding the lines to the wheels.

Another question, did they offer ABS in 88? do you have it?

Poppie51

I thought I had already responded to the last messages but it's not showing up so guess I forgot to hit the send button after writing my message. I don't have the ABS brakes. I was told to bleed the master cylinder this way but it sounds like I was given poor advice. I probably need to rebleed the wheel cylinders again but this time leave the master cylinder alone. The E brakes can be pulled out 12 clicks. It has a space in the beginning where it doesn't start clicking until it's a certain distance out but then you can continue to pull it out for 12 clicks, which looks to be about 2 1/2" overall. The E brake isn't working very well either. The handle gets hard to pull as normal but the brakes aren't holding as they should. I can pull the E brake out and my pedal brakes works better, not perfect but better, so this tells me the pads and shoes aren't adjusted correctly or either there is still air in the line keeping the brakes from expanding properly, although I don't know of any way to adjust brake pads. Am I on the right track here? About a week ago I adjusted the back brake shoes to where they were almost touching the drum and I don't know of any way to adjust the front pads. I will check the rear shoes again to make sure they are set properly since pulling the E brake out seems the give me more brakes. The vehicle has an automatic transmission. The E brake can be pulled out completely and the wheels will still roll. You can tell they are dragging but definitely not stopping the wheels from rotating. I know I contradicted myself on setting the brake shoes, I stated that I had adjusted them, then I stated that they don't seem to be adjusted correctly. I did adjust them but they aren't working properly so I am going to check the adjustment again to make sure it was done correctly since the E brakes doesn't use hydraulics and air in the line shouldn't be a factor as for as the E brake not working as they should. Anyone have any advice? Thanks

akwheeler

You are correct about the operation of the e-brake, it works independently from the hydraulic brakes. if it doesn't lock up the rear wheels either the cables are seized up, the rear brake shoes are not adjusted correctly, or your rear brake drums are coated with oil/grease/brake fluid. it sounds to me like the amount of travel on the handle may be a little much (12 clicks) but you mentioned 2 1/2 inches overall which sounds about right unless you are saying it moves that far after it starts clicking. start by jacking up the rear of your truck and put it in neutral with the engine off, rotate one wheel while you spin the adjuster through the slot in the backing plate (you should hear clicking while you do this), when you feel the brakes drag you will need to reach through the same slot with something I use a curved flathead screwdriver) to release the lever that actuates the adjuster and back the adjuster off a little until you feel no drag spinning the wheel. then repeat this for the other side. If you don't get good e-brake operation after this you need to adjust the cable but do not do this until after you know the shoes are properly adjusted, you may even consider loosening the cables before adjusting the shoes (this will ensure your adjusters work properly).

The front brakes are not adjustable, the pistons extend to clamp the front pads onto the rotors and the square cut seals are designed to pull the pistons back very slightly when you release the brake pedal..

The only other consideration that comes to mind is the size of the rear brake drums, If they were very worn (larger inside diameter from stock) or cracked the curve of the rear shoes will not match the inside surface of the drums and they will not give you much stopping power. You can check this by pulling them off, making sure they are not oil soaked, check for deep grooves and take them to a shop that is equipped to resurface drums, they can measure them easily and compare it to the spec that is cast onto the drum or listed in a book. I wouldn't just jump on letting them turn the drums on their lathe if they offer, it's usually more cost effective to buy new.

Republic77

Total Toyota newbie here, so take this fwiw.
I was taught to start farthest away away from the M/C and work towards it.
right rear, then left rear, then right front, ending with left front.
I don't know if you are doing this, I read the responses but may have missed your sequence.
Also I know that on disc brake cars the rear venting clearance has to be set to get a firm pedal, so I assume the shoes would also need to be in spec also.
hope this helps, good luck and let us know how it turns out.
Trying to get my post count up too!
John

Poppie51

That's the sequence I bled the brakes in but what is the rear venting clearance?

Lift4Reach

x2. Like what akwheeler said, once you've bench bled the system don't reintroduce more air, leave the MC alone. From what you've said so far it may be an installation or adjustment error, I'm late to the party anyways so I'm sure you've figured out that much already.

skypilot

iTrader: (1)

I have wo '88 s. your helper is lifitng on the pedal, before you close he valve. adjust rear brake tigth before bleeding. you are over thinking this.

Republic77

The rear venting clearance on a disc brake car is the space between the pad and the rotor. Too big (far away) and the pedal wont firm up.
Like I said this is the first vehicle I have ever owned with drums so I will take a guess and say that the shoes have to be close to the drum to properly adjust.
I just got my FSM for my truck, and will see if the specs or procedure is in there, however it sounds like what AKwheeler is saying is right.
Also skypilot has good advice,make sure your pedal buddy leaves his foot down while you bleed.
Also
Do you guys use a powerbleeder to do your trucks?

wallytoo

iTrader: (1)

brakes can also be bled without either a helper or pressing the brake pedal. gravity bleeding works. use the same order of operation, don't let the master run dry. i've used this method for over 20 years, and have excellent brakes in all of my vehicles.

Poppie51

Is gravity bleeding done by loosening the bleeder valves and letting the fluid flow out until no air, only fluid, flows out?

wallytoo

iTrader: (1)

yes. do them one at a time, same as normal. it works because the master cylinder is high on the firewall, above the wheel cylinders/calipers.

akwheeler

gravity bleeding is slow and air will try to rise while the fluid is flowing downhill. pressure bleeding moves the fluid fast enough to carry the air downhill and out the bleeder screw. I'm not saying gravity bleeding doesn't work, but I'll stick with pedal pumping. I have had some success with the bleed screws with check balls in them for one man bleeding,

wallytoo

iTrader: (1)

in fact, that is exactly what you are saying.

it works. as does two-person bleeding. both methods depend entirely on doing the process correctly.