Today, on jacks stands run wheels up to 50 mph did the braking to cycle ABS and had my friend hold the pedal after a few cycles. I crack actual brake lines out the ABS, and the lines at the LSPV. If air came out I didn’t see it.
The brake pedal was still sinking under my foot, however, a change is noticed.
This sponge area holds the truck now and don’t have to keep pressing pedal to firmness to hold the truck in gear.
Driving, feels pretty good normal driving. The sponge isn’t nearly as noticeable. I did a max braking up to prior to ABS engaging to a stop, at 70 MPH to a complete stop like I did prior to changing anything on the brakes, before at max pedal no ABS, I liked to have overrun my stop area. This concerned me greatly and that night, I ordered hi performance brakes, rotors, pads, calipers and stainless brake line hoses.
Today same speed, same brake point, stopped like 3 truck lengths sooner, with no abs engagement. Max braking before ABS engagement was my goal.
Truck slowed down nice and nothing odd happened.
Abs works, I did that the day before, Jab the brakes and caused ABS to engauge both front and rear. Performed a really true panic stop. Rear broke loose and ABS came in.
So, there was improvement today, Two pumps, brake pedal is hi, let off and wait then one pedal pump, and is a little lower, maybe 1 inch lower. I wished that wasn’t there, but overall there is improvement.
I saw Toyotapartsdeal had a listing for an ABS unit right under 800.00 , but isn’t available. Japan and UAE have no stock, and higher priced.
I still may order unions and fittings to block the return line to the front, see if I can isolate what system circuit the sponge is on. Air, or leaking dump valve or other.
Tex
Well today, let’s report this as fixed complete. If it stays fixed is yet to be determined.
I don’t believe much in it fixes itself, air in brakes can be tricky… rapid brake reps I have seen had to get air out. Like foams the fluid and air hasn’t formed a bubble yet kinda of thing.
Time sometimes helps, in case Motorcycle TIE the brake lever or pedal on and let it side over night, it amazing results the next day. Why it helps, pushes the air out once a bubble forms. I seen it many times work just like that, overnight good to go.
Well my truck, yesterday a little spongy feel left, normally I check for air, pump twice record brake position, take foot off let it sit. One press and record position. If same then adjustment good on drum, and no air.
That check revealed yesterday, pedal on wait a press , lower pedal about a thickness of a sole of a shoe lower pedal and a little spongy feel and stops the truck fine.
Today, two pedal pump and brake pedal height of Has Pedal height, stops the truck in gear moving slowing.
Take foot off wait, one brake pedal apply and same position now. If not maybe 1/4 of an inch lower to stop the truck maybe. No spong!
If an air bubble was there yesterday and or foamed fluid, the bubble formed and burped it way out the mater cylinder is the only place it could have gone. But it’s gone. Sitting overnight helped it in this case.
Normal brake pedal feel now… omg I am happy about that.
ABS is a great thing when it works, and town driving you need it here in Dallas Ft Worth. Just last night in my 100 I had a max brake effort to avoid an idiot jumping into my lane and slamming on the brakes to avoid traffic stopping. I easily slowed but it’s the person behind me and behind them that worries me. If they are paying attention or not.
That lack of attention is where ABS will
And can help. Under panic mode you do not have fine motor skills to regulate foot pressure very well. Then Slide to impact normally happens. Last night that happened almost when I saw the car behind me nose dive and I stepped out on the shoulder and they parked in my spot. My wife freaked out a
Until she saw the car come up beside us.
Anyway I wanted to keep the ABS working if I could and it is currently. Hope it stays that way.
The fix , magor determination, jack the truck up, all
4 wheels , spin wheels up, apply brakes enough to engauge the ABS. Hold pedal and bleed.
I started ABS out lines and worked my way back to the actual lines on the LSPV. Took some doing… but it worked.
I have a pressure bleeder and master cylinder adapter and pressure bleed the brakes. That didn’t help at all. Cycling the ABS did.
I tried pressure bleeding and hot wire ABS motor and dump valves, that didn’t help.
Actually foot brake pressure and cycling the ABS had results. I actually drove it and engaged ABS 6 times on gravel. Resulted in no improvements.
Only bleeding immediately after cycling the ABS resulted positive results in my case.
I check for TSBs on this issue and found non.
This is a temperamental system the worse I have ever ran across in working on cars / trucks since 1983 professionally. 1 gen 1800 Goldwing ranks number 2 as difficult bleed. Speed bleeders on that makes it easy now, and know the sequence.
Good luck to any others with this issue.
Tex
