My old truck

[Handy Andy]

The truck didn't seem to pull either direction and I didn't notice any pulsation in the break pedal. But when I would pump the brakes and try to build pressure it wouldn't build any no matter how long I pumped the brakes.

These signs lean me back in the direction of the Master cylinder where the Brake Fluid reservoir resides. Loss of brake action occurs when you have lost containment of the system, or the pressure seals in the system are not working

You seem to get brake pressure, but nearly to the floor - so you may have air in the system - or low fluid - so pull that cap and check, fill as necessary, and then look around for your brother, or family member so they can sit in the Drivers seat and press the brake pedal for you so you can bleed the brakes.

That is only if you crack open the bleeder valves and can't see if fluid burps out.

Then you may have another type of braking problem - dealing with the pushrod that the brakepedal has, is not retracting fully,

This fail to retract problem makes for a pedal that goes to the floor if only to apply some pressure - because the port used to refill that upper chamber that is where the piston pushes against - is not able to open and refill the upper hydraulic side of the Master cylinder.

More than likely it is in the front calipers that these air pockets have formed.

But to get at them, you'll need to make sure your booster is fully hooked up to the vacuum from the Intake Manifold. Vacuum leaks are not fun. The Booster helps to pull the pushrod back out so the cylinder can then fully release into the "at rest" position and open the ports in the system. See if the pushrod will then retract and fluid will get into the brakelines. See if you have a broken hose, start digging.

Because if fluid does not come out when you crack open the bleeder valve - this system is a ":gravity feed" where once ports are open, fluid is pulled thru by it's own weight and pressure from above in the tank for that side of the system. If a line is leaking you'd see fluid below where it was parked.

You don't have that condition, what you have a pedal that nearly has to go to the floor to get the pistons to move enough fluid to apply the pads and shoes. That tells me either you're out of fluid - or you have plugged lines - you wouldn't have brakes if that was the case - or your Master cylinder is out of alignment to the booster it bolts to, affecting the pushrod clearance - and to remove those possibilities, check to make sure you have vacuum in the system to pull the booster back into a resting state to help that push rod do the same - so they both can let fluid enter in so you can re apply the brakes as you need to to get pressure to build. To check for that you'll need to know if the bleeder valves are open and letting fluid escape to prove the ports are aligned.

 

[G-Golly Wally]

Remember that when you have the wobble, the calipers were pressed back into their pistons due to the freeplay in the hub. The studs to the wheel need to be tightened too. It may take several attempts to torque them down an seat them to the hub.

If the truck sits and this occurs more often - then you'll need brake work, not necessarily at the calipers or the Drums, but at the Master cylinder. The lines from it to a proportioning valve (I don't have you're truck in front of me) that equalizes the brake pressures so the vehicle don't lock up a set of brakes when you panic stop.

The valve is (was) working against that wobble and may have affected the rear drum wheel cylinders due to the runout caused by it.

A pulsation occurs when the brakes fluid drips onto the lining and the shoes roll onto and thru it- generating a slip you feel as a pumping action - that means the lining is contaminated with the brake fluid.

To isolate this, drive the vehicle and as you brake to a stop, feel the way the truck pulls, tugs or drifts as it stops. That provides the biggest clue as to wher, and what side is affects of a system.

Vibration thru the steering wheel tells you the fronts are bad, but a pulsation thru the brake pedal only, tells you to look to the rear drums or calipers to as they are not hitting against the steering arm and control/tie rods.

I bled the front calipers this afternoon and it seem to help the breaking some. I had my wife helping and she wears down pretty quick when pumping the breaks for me. Gonna have my daughter help next and bleed front and back calipers. Right now I have a slight pull to the passenger side. I can build pressure by pumping the break and I couldn't last time I tried. It acts like the breaks are gonna catch at their normal spot for a second and then continues to almost the floor. But I do have more breaking than I had previously

 

[Holydvr]

Last time I ran into this situation, the master cylinder was defective but not leaking. Just an idea.

 

[G-Golly Wally]

Last time I ran into this situation, the master cylinder was defective but not leaking. Just an idea.

Yeah, I kinda wonder if that's what is going on. Still need to bleed the breaks a again if I can get my daughter to help me. She seems to be to busy nowadays. Anyway if bleeding again doesn't help its going to my buddy Keith.

 

[Shadetree Mechanic]

I like to use the "Gravity Bleed" method. This is what I do if one of the kids isn't around to push the pedal.

Crack open the lid of the master cylinder, then crack open the bleeder at the farthest wheel first. It should start to dribble out of the bleeder, make sure you keep an eye on the fluid level. I often do other quick tasks while doing this. When the level gets low, close the bleeder, top off the fluid, and go to the next closest wheel and repeat.

 

[Holydvr]

I use the vacuum pump setup. Its a hand operated pump that has a reservoir on it. Dont have to pump the brakes. The gravity method works well also, but I just figured the pump could speed it up a bit when needed.

 

[Shadetree Mechanic]

I use the vacuum pump setup. Its a hand operated pump that has a reservoir on it. Dont have to pump the brakes. The gravity method works well also, but I just figured the pump could speed it up a bit when needed.

I had one of those, they work well. My kid broke it and I haven't seen it in a long time.......

 

[G-Golly Wally]

Well, i believe the master cylinder is bad because another bleeding didn't help still have the same result. Called my buddy Keith and he thinks the same thing so it's going to his shop Friday. Told him i have to go back to work next week so its not like i need it done immediately just fix it when you can and I'll pay ya when i get back home.

 

[G-Golly Wally]

Got the master cylinder replaced so the brakes are now working. Ordered some goodies, will be putting them on when I get home still waiting on the headlights to arrive may be awhile.

 

[unit_399]

It is foolish to buy a new vehicle right now. This is especially true if talking about GM, Ford and Ram. Quality control is at all time low and price is at a record high. That is not the time to buy. The repo market is slowly exploding which will drive prices down some.

Even if an otherwise old truck that runs great needed a $5000 to $7000 transmission that would be a bargain right now!

I am sure your wife is a great person and wonderful wife but I think she is out of touch with the reality of what the world is doing at this moment in time. Now if you are made out of money and the insane price combined with lowest ever quality control and durability means nothing than I could see her point of view.

Have you tried explaining this to your wife?

I buy Toyota's then drive them for 20+ years usually doing nothing but plugs, belts, brakes, oil changes, air filters, coolant and struts over that 20 years! IF not for road salt and rust they would last even longer. My family drove one for 29 years but we did repaint that one at 19 years. It was sun backed from 6 years in Georgia before moving to Michigan! It is still on the road in my area. It has been repainted a few times. That one is 36 years old and used hard off road all the time.

Right now is the time to make the repairs and kick the can down the road until things improve unless your made out of money! The insanely high prices combined with inflation is what is feeding the repo market like no other time in history!

 

[TM86]

Got the master cylinder replaced so the brakes are now working. Ordered some goodies, will be putting them on when I get home still waiting on the headlights to arrive may be awhile. View attachment 67160View attachment 67161View attachment 67159View attachment 67162View attachment 67163

Let us know how those work out. Last time I tried LED bulbs they didn't have the right amount of resistance and so the blinker relay acted like there was a dead bulb somewhere. Interested to know if they've solved that problem.

 

[Smokinone]

Let us know how those work out. Last time I tried LED bulbs they didn't have the right amount of resistance and so the blinker relay acted like there was a dead bulb somewhere. Interested to know if they've solved that problem.

I had that problem in the past as well, I think I installed a resistor somehow to get it going. Been a long time since I did that, but I eventually just went back to the tried and true incandescent bulbs after having so many LED failures.

 

[G-Golly Wally]

Let us know how those work out. Last time I tried LED bulbs they didn't have the right amount of resistance and so the blinker relay acted like there was a dead bulb somewhere. Interested to know if they've solved that problem.

Will do. These are supposedly plug and play, so hopefully I don't have any issues. According to reviews others with the same truck as mine had no issues. But usually I'm not that lucky.

 

[Handy Andy]

What many experience when they switch from older "bulb" headlamps and Turn Signal - even rear Brake lights, are the "Rapid flash" - which is caused by the LACK of current the new updated bulbs consume. So the thing thinks the circuits are "open" (LED + Dropping resistor / Power module) - it's a high-impedance low-power consumption device, so it puts it in rapid flash - this sucks when you use the older "thermal flasher" units found in older trucks and even newer ones. They used these as redundant backup on 4-way flasher so the units needed a load to "heat up" the internal bi-metallic strip to deform - pop off the internal contact - then cool and recoiled back to original shape - then repeat.

They tried phasing these out as time progressed - however due to redundant needs and DOT considerations for "Backwards compatibility" use, they still used them - up to about 2004 when the newer LED Modules and integrated headlamp units came out after their testing for durability finally got them DOT approved - whatever that means these days.

The solution in many of them is to place an 6~12Ω - 20~50W Wire wound resistor - or simply more of a 1W wire wound embedded - epoxied in, a package that can dissipate the heat the resistor generates without burning up - ACROSS the wires that went to that lamp - being replaced by the LED.

The problems with this is the filament - it needed an inrush current to light that lamp - acted like a near dead short, using a lot of current until the filament heated up and the lamp looked like a higher-impedance load.

Thats how those thermal flashers worked, and they took on the load the lamps produced with ease - they parallel a wire of known resistance in a strip and combined with with a bi-metallic strip made up with the bends - so as the Nichrome wire passed current - it also passed thru the strip - heating both up, then the circuit opened for a moment and the Nichrome wire took the brunt of the high-impedance heated filament until the impedance changed back to low-resistance high-current demand - the lamp went dark until the dead short the lamps looked like, heated that bi-metallic and Nichrome together at the same time pulled the strip to short that contact out again and pass the power onto the load.

LED's need power yes, but in mA not A - so they can't pull enough current thru the flasher to make it work.

So the Carmakers are doing a workaround using Power modules with built in -timers that take care of the flash problem - but the cost is now you're stuck with the LED compatibility with low-current or power demands versus just using a simple filament bulb with that quirk of having a high-demand instant that when taken care of - works well and doesn't draw a lot of power - similar to LED power consumption.

 

[G-Golly Wally]

got the tail lights, break lights, 3rd break light and new mirrors on yesterday. So far everything has been plug and play with no issues. My headlights are still a week out so those will get installed after I get home next time.
Had to add a picture of my two helpers, they think it their truck. When I fire it up they think its go time! At least they're easy to load up for a trip to the veterinarian!