Total brake failure

[oskarkat]

Pulling the truck out of the shop this morning was interesting....no brakes!


I normally pull the truck off to the right so I have access to the shop door but today I needed the old wastewater building to stop me from this....



A fifteen foot drop into the creek.



My shop is in an old whiskey distillery. I make stuff like this.


There were no obvious brake fluid leaks from anything, master cyl was full. I guess a new dual res. master cyl upgrade is in my immediate future.

[vacca rabite]

My bet would be all the cylinders on your drums are rusted shut. Pretty common.

I nearly drove my truck through my neighbors living room the first time I drove it (and found out it had no brakes). E-brake slowed me down, and I cut hard right and let it drift up a hill, drove back into my driveway and parked it for a full brake re-fresh (that has since led me to other work).

Zach

[wrecker]

Cool looking shop. Nice truck too.

[Barrman]

Glad nothing was hurt.

I drove my truck to work yesterday. The brakes felt fine, but when I got out, I noticed I left a foot print on the pavement. Looked in the truck and the firewall was wet.

Once I figured out by popping the caps it was the brake master compared to the clutch master. I pulled it off. This is a 5 year old NAPA bought 1976 Corvette master. One of the big cast iron things. The secondary seal for the secondary piston was leaking. We pulled the pistons out and it was full of rusty crud.

The seals were ok, just dirty. We cleaned them and the cylinder up. 3 spots had some pitting. The kind you can barely see but not really feel. I needed to get home and they weren't where the leaking seal was, so back together it went. Brakes are fine now and the firewall needs to be repainted.

My point of this story is for you to think real hard about swapping over to DOT 5 when you redo your brakes. Mine had all new DOT 3 in it and rusted out. Flush and DOT 5 swap over will happen this weekend for me.

[randyscycle]

Lucky that you weren't headed down the highway when that happened......

Check those brakes!!!! Nothing like a vehicle that without warning decides not to stop. Pull all four wheels and do everything it needs, or might need. Given the weight of these trucks, I'd do all new steel lines, rubber lines, a dual master cylinder, and shoes, and wheel cylinders. Cheap insurance in my opinion. A lot cheaper than a collision.

[dave]

my wheel cyl.s seased up after setting for 3 years of minimal driving and now im only running on the rear brakes as I only changed the rear ones and havent changed the fronts yet. I figured someones rear bumper would slow me down if needed. LOL!

[redneck1]

Dave,you NEED a bumper like mine.



It ain't bent yet.
Redneck1

[wolf.dose]

Brake problems have several reasons! First is low milage a year, means the brakes are not used. Brake fluid is hydroscopis, means it will pic up water from the humidity of the air.
Second is long time no service, which means old water containing brake fluid (and also some other debris, looks very nice braun in color, when you bleed your slave cylinder)
Change to a 2 circuit system: I use a CJ7 drum / drum master cylinder. And properly overhowled wheel cylinder. Means they have been taken apart completly, cleaned in pure alcohol, reworked to a perfect inner shining surface, regreased with brake grease blue, f.e. from Tewis /ATE (Tube with 300 ml, will last for livetime), reassembeled and new brake fluid with propper bleeding.
Additionally I reduced the rear wheel cylinder to 15/16" size to get a better brake balance. The M715 series is made in a time where rear blocking wheels were prefered, howerver this reduces braking performance very much. With my modification I get to a deceleration of allmost 70 percent compared to 40 percent (or 7 m/s² compared with 4 m/s²). An additional hydraulic booster makes the braking as comfortable as a passenger car!
Wolf