Wierd Brake Issue

[tim71]

My 72 Blazer build is 98% done but I've got a brake issue. If you stop in a normal manner without heavy braking the brakes operate normally. However, if you stop hard or even push pedal hard while stopped, the brakes will momentarily (2-3 seconds) stick and hold the Blazer then release. If you are going 50 mph and apply hard brakes and release at say 30 mph they will also stick and then release after a couple seconds. When they release you can feel a small thud thru the brake pedal.

Every brake component is new except for the front rubber brake hoses from frame to caliper. The brake pedal and linkage to the booster seem to be operating correctly. I'm not to anxious to change these hoses because I don't want brake fluid everywhere. Seems to me that if the front hoses were bad, they would not release at all and cause the brakes to drag. As a test, I also put a washer between the mc and booster to see if that rod was to long.

Any ideas?

[biketopia]

I would start with front hoses..they fail internally and will act as a one way check valve. Is this a disc front drum rear?

[cadillac_al]

I just replaced a couple of brake hoses on my Chevy motorhome. They were acting up intermittently for a couple years until they started making the brakes drag all the time. I should have replaced them the first time I suspected them.

[c30]

Absolutely, it's the hoses. I have a 67 c30 with drums that was braking like that. Went to bleed the brakes and it actually took a little foot pressure to get the fluid to come out.
I had heard about old brake hoses collapsing and these were probably original to 1967.
I replaced all three and once I started bleeding them I could tell, right away, that this was the issue.