I realize this is the 100-series forum, not a 4Runner forum. But, I also own a '99 LC which is equipped with the hydroboost brakes and I have read some threads here talking about the complications that go along with system failures and repairs. I'd like to share my experience with my '05 4Runner brakes because it will likely have some crossover and usefulness for any Toyota built within the last ~20 years that has the same type of hydroboost braking system (meaning no traditional old-school brake booster)
I recently purchased a '05 4Runner SR5 V6 for my wife and kids to drive so that my beloved 100-series can stay a garage queen. Let's all be honest, a 4Runner is a much more expendable vehicle and a whole lot easier to replace than a low miles, well-maintained LC like mine. The 4R had a good maintenance history and ran well considering it had 195K miles on it. But it only cost me $6,500. And even though it's 'expendable', it's still a very reliable, competent and safe vehicle for the family to be in.
I didn't do the best job inspecting the vehicle before deciding to purchase it and realized a few days after closing the deal that there was something wrong with the braking system. Whenever the key was on or the vehicle was running, I could hear this faint 'thunk' sound and feel something in the steering wheel and pedals. This repeated every 10 seconds, regardless of being stationary, driving, etc. I started to investigate what it was and eventually diagnosed this as the boost motor/pump cycling on/off every 10 seconds. I had a friend with Techstream hook up and discovered that the pressure sensor in the master cylinder was constantly cycling up and down. My diagnosis was that the accumulator or the check valve in the pump was not holding pressure. The motor was doing what it was supposed to, keeping the system pressurized. They system just wouldn't stay pressurized for very long.
Now if you take your vehicle to Toyota with anything related to the master cylinder, they will likely instruct you that you need to replace the entire unit, to the tune of $3,000 - $3,500. Being cheap and resourceful, I started investigating what to do to avoid that high cost, mostly from posts I found on the toyota-4runner.org forum.
I eventually decided to purchase a used brake master cylinder assembly from a salvage yard. $300 from a salvage yard in San Diego (ebay) got one from a 2010 4Runner that had 70K miles on it.
Rather than reposting all the rest of the details here, I'm just going to send you to my original post over in the High Desert Cruisers club forum, because I'm lazy. I hope this helps some folks out. Enjoy.
Bought an '05 4R for Danise and the kids
You can also find my write-up on the T4R forum here:
http://www.toyota-4runner.org/4th-g...ulator-bleed-brakes-manually.html#post3162798
I recently purchased a '05 4Runner SR5 V6 for my wife and kids to drive so that my beloved 100-series can stay a garage queen. Let's all be honest, a 4Runner is a much more expendable vehicle and a whole lot easier to replace than a low miles, well-maintained LC like mine. The 4R had a good maintenance history and ran well considering it had 195K miles on it. But it only cost me $6,500. And even though it's 'expendable', it's still a very reliable, competent and safe vehicle for the family to be in.
I didn't do the best job inspecting the vehicle before deciding to purchase it and realized a few days after closing the deal that there was something wrong with the braking system. Whenever the key was on or the vehicle was running, I could hear this faint 'thunk' sound and feel something in the steering wheel and pedals. This repeated every 10 seconds, regardless of being stationary, driving, etc. I started to investigate what it was and eventually diagnosed this as the boost motor/pump cycling on/off every 10 seconds. I had a friend with Techstream hook up and discovered that the pressure sensor in the master cylinder was constantly cycling up and down. My diagnosis was that the accumulator or the check valve in the pump was not holding pressure. The motor was doing what it was supposed to, keeping the system pressurized. They system just wouldn't stay pressurized for very long.
Now if you take your vehicle to Toyota with anything related to the master cylinder, they will likely instruct you that you need to replace the entire unit, to the tune of $3,000 - $3,500. Being cheap and resourceful, I started investigating what to do to avoid that high cost, mostly from posts I found on the toyota-4runner.org forum.
I eventually decided to purchase a used brake master cylinder assembly from a salvage yard. $300 from a salvage yard in San Diego (ebay) got one from a 2010 4Runner that had 70K miles on it.
Rather than reposting all the rest of the details here, I'm just going to send you to my original post over in the High Desert Cruisers club forum, because I'm lazy. I hope this helps some folks out. Enjoy.
Bought an '05 4R for Danise and the kids
You can also find my write-up on the T4R forum here:
http://www.toyota-4runner.org/4th-g...ulator-bleed-brakes-manually.html#post3162798
