Spongy Brake Pedal. At witts end
#21
Registered User
Thread Starter
Ill give that a shot next, as I do have a lift. I was so frustrated with it the other day, that i almost traded my cherry firstgen for a nice fzj80. Thankfully i didnt. I just think its so very weird that i will have good stiff pedal with a lot of stopping power sometimes, and seemingly randomly my pedal turns to SH... Crap... and i almost rear end someone because my pedal is mush
#23
Registered User
The portioning valve on the rear axle is bad. If the brake behaviours changed when you messed with it then it is the problem. Im betting its allowing to much fluid to the rear thus starving the front brakes and giving you a mushy pedal.
#24
Registered User
Thread Starter
Sorry for not replying sooner fellas.
So Update:
1. I cut my LSPV arm and used an adjustable turnbuckle to set the length and secured it to the arm pretty well with a few zipties... ghetto i know but it actually works. Thanks 4crawler. (minus the zip ties)
2. I was seriously so sick of the brakes on my truck that I decided to go to napa, buy 1994 T-100 V6 Calipers for both sides, Ceramic Brake pads, T-100 Rotors, and My buddy had a pristine Dual diaphragm brake booster/ 1 inch bore Master Cylinder from a 1994 v6 4Runner.
I removed all of the 4cyl garbage, removed my MC and booster and smashed it with a ball peen a few times. Im pretty sure they were junk anyways, there was a lot of brake fluid between the MC and booster. Then I installed the booster and MC and bled the MC. I saved the calipers because the core on them was $65 bucks each, so I couldnt launch them into orbit. Installed the new Rotors, trimmed some of the back plate with an angle grinder, bolted up the calipers and installed the pads. I then bled all 4 corners and adjusted the rears AGAIN... then gave it a test drive.
The first press of the brake almost sent me through the windshield as i reversed out of the driveway. I was not used to this ridiculous of braking power, I Sh you not... The upgrade in braking is so incredibly great it is absolutely ridiculous. This should be a MUST DO upgrade. It is time consuming, and every time I said "I" up there ^ I meant myself and a friend darnell who is the man. I have never taken the hubs apart and he seemed like he was born inside of those things. He knew em inside and out... thanks man
The braking now is so effortless for a ridiculous amount of stopping power. My LSPV is bad, it makes a metal to metal "shink" noise like two swords scraping against each other when you press the brake down hard. You can feel it on the brake line that leaves the LSPV and goes to the rear brake drums. Im going to put a willwood or somthing in there next and hopefully get rid of the load sensing part. Thanks everyone for following through my high blood pressure stressful pull my hair out saga of brakes... Feel free to ask any questions.
Dont ya love brand new shiny parts? too bad they dont stay looking like that all of the time.... Almost makes me want to put some 24 inch american force wheels on my 4runner so I can show off my bling bling brakes
So Update:
1. I cut my LSPV arm and used an adjustable turnbuckle to set the length and secured it to the arm pretty well with a few zipties... ghetto i know but it actually works. Thanks 4crawler. (minus the zip ties)
2. I was seriously so sick of the brakes on my truck that I decided to go to napa, buy 1994 T-100 V6 Calipers for both sides, Ceramic Brake pads, T-100 Rotors, and My buddy had a pristine Dual diaphragm brake booster/ 1 inch bore Master Cylinder from a 1994 v6 4Runner.
I removed all of the 4cyl garbage, removed my MC and booster and smashed it with a ball peen a few times. Im pretty sure they were junk anyways, there was a lot of brake fluid between the MC and booster. Then I installed the booster and MC and bled the MC. I saved the calipers because the core on them was $65 bucks each, so I couldnt launch them into orbit. Installed the new Rotors, trimmed some of the back plate with an angle grinder, bolted up the calipers and installed the pads. I then bled all 4 corners and adjusted the rears AGAIN... then gave it a test drive.
The first press of the brake almost sent me through the windshield as i reversed out of the driveway. I was not used to this ridiculous of braking power, I Sh you not... The upgrade in braking is so incredibly great it is absolutely ridiculous. This should be a MUST DO upgrade. It is time consuming, and every time I said "I" up there ^ I meant myself and a friend darnell who is the man. I have never taken the hubs apart and he seemed like he was born inside of those things. He knew em inside and out... thanks man
The braking now is so effortless for a ridiculous amount of stopping power. My LSPV is bad, it makes a metal to metal "shink" noise like two swords scraping against each other when you press the brake down hard. You can feel it on the brake line that leaves the LSPV and goes to the rear brake drums. Im going to put a willwood or somthing in there next and hopefully get rid of the load sensing part. Thanks everyone for following through my high blood pressure stressful pull my hair out saga of brakes... Feel free to ask any questions.
Dont ya love brand new shiny parts? too bad they dont stay looking like that all of the time.... Almost makes me want to put some 24 inch american force wheels on my 4runner so I can show off my bling bling brakes
Last edited by dbbowen; 09-25-2016 at 07:40 PM.
#25
Registered User
Thread Starter
Also, it seems that since i have done this swap, even if i move the arm of my LSPV all the way up my fronts still lock up before the rears. The front brakes are just a lot stronger now i guess...
#26
The following article is worth a read IMO:
http://www.stoptech.com/technical-su...alance-matters
....the more applicable stuff is toward the end.
#27
Registered User
Thread Starter
Yeah i can see what they mean in the article. I do not have a further stopping distance though, the truck stops on a dime. I do still need to install a manual proportioning valve though. Im almost certain that my stock lspv is not properly functioning.
#28
Yeah, many factors at play. You also have to consider what you're starting with. ....which in my case (re: my '86 T4R) isn't anything I would say was close to satisfactory.
#29
Registered User
Thread Starter
haha yeah my 87 is the same, the brakes were terrible with the 33 inch tires I have on it. I mostly did this brake upgrade because I am about to move up to 35s in the near future. That would have made the brakes even worse.
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Kj94runner
86-95 Trucks & 4Runners
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01-27-2016 12:01 AM