complete brake failure

[USBRIT]

This is my first post on here so am saying hello all.

Just over a month ago I went to town in my 2001 Chevy 1500 Silverado on a really hot day to meet someone I had never met before and sat with the engine running for about 20 minutes met the guy sold him a winch and started home, I noticed the water temp was rather high and figured it would cool once driving as it did. I got about 5 miles and going down a hill my brakes completely failed I had no immediate danger so I let the truck slow and stop called a wrecker to get it home when I got in my truck to pull it in the garage to check it the brakes were working perfectly I road tested still worked okay.

 What I am wondering is it possible the brake fluid in the master cylinder got so hot that any water in the fluid boiled and caused air in the lines I read an article somewhere that it can happen, I bought a new master cylinder but haven't installed it yet because I dont use the truck as a daily driver infact rarely use it. The brakes still work to this day.

 

 

[1970judge]

Yes, its possible. Down hill riding the brake is a good way to do it easily. But yes, you can boil brake fluid. Us track folks swap fluid as the first track mod. In a normal DD it shouldnt ever need higher BP brake fluid unless your truck will see severe duty. Would seem rather odd, but, if the hill was really working the brakeS over (or you have a stuck caliper)  It can happen. 

[USBRIT]

7 hours ago, 1970judge said:

Yes, its possible. Down hill riding the brake is a good way to do it easily. But yes, you can boil brake fluid. Us track folks swap fluid as the first track mod. In a normal DD it shouldnt ever need higher BP brake fluid unless your truck will see severe duty. Would seem rather odd, but, if the hill was really working the brakeS over (or you have a stuck caliper)  It can happen. 

I had in the previous three months replaced all calipers and brake pads and none of the calipers appeared to be stuck I will check again I am going to put the new master cylinder on and change the fluid out. 

 Sorry I put calipers it should have been discs and pads I just saw a post saying I replaced all calipers and pads sorry for the incorrect information

[muddkatt]

So you replaced all four calipers and pads about 3 months ago?

[USBRIT]

7 hours ago, 1970judge said:

Yes, its possible. Down hill riding the brake is a good way to do it easily. But yes, you can boil brake fluid. Us track folks swap fluid as the first track mod. In a normal DD it shouldnt ever need higher BP brake fluid unless your truck will see severe duty. Would seem rather odd, but, if the hill was really working the brakeS over (or you have a stuck caliper)  It can happen. 

I had in the previous three months replaced all calipers and brake pads and none of the calipers appeared to be stuck I will check again I am going to put the new master cylinder on and change the fluid  

I made a mistake I meant to write I had changed discs and pads not calipers sorry for the wrong          information the calipers I used a c clamp to gently put the pistons back into the calipers I didn't notice any resistance other than that caused by the fluid being pushed out into a collection jar connected with a rubber tube.

I do apologize for the mistake.

[intheburbs]

I see two likely candidates, both happened with my '01 Suburban, on separate occasions.

 

1) The brake lines are prone to rust and can fail.

2) The master cylinder failed

 

ETA: DOT3 brake fluid doesn't boil until over 400° F.  Nothing short of an engine fire will boil it off.

[USBRIT]

I understand what you are saying I just dont understand the loss of brakes which I put down as master cylinder hence I bought one but the brakes have been okay ever since