Brakes Stuck on Resulting in Blown Lines

[piperpilot1363]

Hey Ladies and Gents,

Driving home yesterday (in a blizzard, naturally) my I depressed my brakes only to find the pedal not returning. Because of the poor visability, I forced it to the next exit before the wheels locked and I went for a ride. The brakes basically stayed engaged, with the pedal down, resulting shortly thereafter in a dual line blow out. Just before the blow out I heard something "whined up" and the pedal came back up, but then the lines failed. I think the lines blowing is a secondary problem. I had the brakes lock once before but was never able to replicate the problem. Any thoughts on why the pedal is staying down/ brakes remain engaged?

Its a 1986, 2wd, 2.3L with 116000 or 216000 on it.

Thanks

 

[adsm08]

Very possible the fluid froze.

 

[alwaysFlOoReD]

I never really thought about brake fluid freezing but brake fluid "likes" adsorbing water so I can see this happening, especially after almost 30 years. Time to do a flush.

Richard

 

[RonD]

Power assisted brakes have an "atmosphere" valve on the cab side.

When you press down on the pedal this valve opens and the 15psi(sea level) of pressure comes in to the assist cylinder, since there is less than 15psi of pressure on the "vacuum side" of the assist cylinder this difference in pressure assists you in pedal pressure.
If the return valve or spring is not working then pedal will not return and pressure stays on

 

[adsm08]

Power assisted brakes have an "atmosphere" valve on the cab side.

When you press down on the pedal this valve opens and the 15psi(sea level) of pressure comes in to the assist cylinder, since there is less than 15psi of pressure on the "vacuum side" of the assist cylinder this difference in pressure assists you in pedal pressure.
If the return valve or spring is not working then pedal will not return and pressure stays on

Which would account for the stuck pedal, but not the exploding lines. Just holding the pedal in at full assist should not be enough to blow out lines.

Ron does have a point about the booster and/or return spring being the likely cause of the pedal staying down.

 

[martin]

I've had the pedal stay down when the booster failed due to one side rusting out. Failed lines could also be due to rust.