2005 Tundra brake failure

Earlier this summer we were having intermittent brake issues on our 2005 tundra
The pedal would go to the floor sometimes

If we left it for awhile it would work again
We purchased and installed a master brake cylinder at a shop

All has been good till last week when they failed and our staff rear ended another vehicle.

No one was hurt but our staff are pretty unsure about getting back in it.

I’m trying to figure out why it failed. Does Tundra have brake issues? Might we have bought a faulty master cylinder?

Do you know of any history on Tundra brake failures?

 

Welcome aboard from SoCal.

 

Sorry for the incident and glad to hear everyone is ok.
In order for fellow forum members know more about the issue, I have following questions for you.

When the master cylinder was replaced, what else did the shop do? Did you replace the brake booster as well? Are the parts replaced aftermarket or genuine Toyota parts? Does the truck loose any brake fluid? Does the brake pedal always firm when be pressed?

 

Multiple instances of the pedal going to the floor would have set off very loud alarm bells for me. If I were one of your staff, I'd have refused to drive it until it was repaired. If I were in charge, it would have gone straight to the shop. The legal liability of allowing an employee to drive a known defective vehicle is massive, and a decent (or even half decent) lawyer would easily get a big payout on that case.

Master cylinders wear out, and bad rebuilt master cylinders happen. If the shop that installed the master cylinder didn't properly flush and bleed the system, you could have water or air bubbles that caused the failure. Have it towed to a mechanic qualified to service antilock brake systems and have it checked out.

I'm not aware of any issues with Tundra brakes, but contaminated brake fluid happens. Water collects and causes rust inside the master and slave cylinders. Air in the lines can happen when the water freezes in the slave cylinder and causes air to seep in around the seals. Flushing the system and bleeding the brakes is a good start. A good mechanic should be able to sort it out and get the truck back on the road in safe condition.

 

we did pull the truck out of service when the bell started ringing thanks

 

About 2 weeks ago, the red brake warning light came on and stayed on after I released the emergency brake. I carefully drove to my independent garage. The master cylinder was leaking brake fluid and the red light comes on when the brake fluid is low. The garage installed a new master cylinder and inspected all brakes, lines, etc. The brakes were all in good condition. The mielage on the vehicle is about 270,000 miles. This is the second master cylinder replacement since I bought the 2002 Tundra 4.7 Limited access cab new in October, 2001. The Toyota OEM master cylinder failed at about 170,000 miles and the replacement failed at about 100,000 miles.