Need some technical help i.e. I'm stuck (1 Viewer)

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Joined
May 29, 2020
Threads
7
Messages
112
Location
Huntsville, Al
Hey all!

I am amazed on how reliable Toyota Land Cruisers are. I have owned mine for only 8 months and it has been in my barn for only 5 of them! I even got to take it to a club meeting one time! But just once.

I have hit the limits of my knowledge on two things:

First: I have had mushy brakes, so I decided to rebuild the brakes. Like all of them. I have replaced the vacuum boost, master cylinder, all rubber hoses, and all calibers. Now, the brake pedal feels tight after bleeding the brakes (in the order Rear right, rear left, front right, front left and finally proportional valve). As soon as I turn it on and apply the brakes with the vacuum boost on, the pedal slowly sinks to the floor. I feel like I am missing something unique to the vehicle. Is there a way to bleed the ABS?


Second: my CDL was working great after replacing the 84222-12010 switch in the front of the transfer case (about 4 months ago). Last week when I shifted into LO, the CDL light didn't come on and I did not hear the actuator whirl. I think it is the L4 Position Switch, so I pulled it today. First off, the L4 is not a PN 84222-12010. What part number is it? Second off, when I depressed the switch with the multimeter, I was reading ~70 ohms, which seems normal to me. I read the voltage across the plug for the switch at 9.81 Volts, while disconnected. Then I tried jumping it with a paper clip, and nothing happened. What am I missing?
CDL L4 Switch.jpg
 
I bought a pressure bleeder and it helped me. You can borrow it if you like. There is a way to activate the ABS with a 12v power source and pigtails. If you search on here you can find it.
 
A sinking pedal can be caused by a few things. How much pressure is applied when the pedal sinks can give hints to where the failure is. I'd need to see it to keep the poking in the dark to a minimum.

As for the 4lo shenanigans, those switches are notoriously glitchy at end of life. They should be open or closed you shouldn't see resistance if the switch is healthy. Looks like oil got in yours and is causing erratic behavior, not uncommon. Sending a pm.
 
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80 brakes can be a bastard to bleed. Best option is to use a pressure bleeder. Since you replaced practically everything is there is no telling where the air is. That system has air in it somewhere.

As for the 4Lo, throw a switch at it. Yours looks like it's seen better days, and that is the common denominator right now
 
Yeah I will put a new switch in. I'm concerned that when I jumped the connector to the switch there was no change. I would have thought the light would come on the dash I would hear the actuator actuate.

Yeah I would love to borrow a pressure bleeder! And if anyone wants to swing by to help that would be amazing!
 
Yeah I will put a new switch in. I'm concerned that when I jumped the connector to the switch there was no change. I would have thought the light would come on the dash I would hear the actuator actuate.

Yeah I would love to borrow a pressure bleeder! And if anyone wants to swing by to help that would be amazing!

PM me your number. I’m a bit busy to help out but if you swing by and grab it I can show you how to get it done.
 
Ok, so hear me out. You know the 7 pin mod with the switch on the dash? What if I just bypass the L4 switch and just wire a switch directly to my dash board... because I did already.

manual switch.jpg


The CDL locks now just fine.

Is there anything preventing me from locking the Center diff in high?
 
Nope, go ahead. 100s got that functionality from the factory with the same transfer case.
 
Nope, go ahead. 100s got that functionality from the factory with the same transfer case.
So this sensor doesn't change any other "setting" by making the transmission think it is in low when it isn't?
 
Shift points move somewhat and the ABS disengages when the ECU sees a change from Hi to Lo. Locking it on pavement in high range carries with it all the normal burdens of a normal 4wd in 4HI: gets hard to turn, acts squirrely, binds up the driveline, etc.
 
Shift points move somewhat and the ABS disengages when the ECU sees a change from Hi to Lo. Locking it on pavement in high range carries with it all the normal burdens of a normal 4wd in 4HI: gets hard to turn, acts squirrely, binds up the driveline, etc.
Perfect! thank you.
 
I replaced the master cylinder and got no change. After reading threads about the ABS I am convinced that this is the issue.

I followed the steps listed here: Is there a way to trigger ABS actuator to combat spongy breakes? - https://forum.ih8mud.com/threads/is-there-a-way-to-trigger-abs-actuator-to-combat-spongy-breakes.309314/

However my ABS actuator didn't respond. In fact, if I never had the ABS light ever come on, ever for any reason.

I am leaning towards deleting the ABS per: Yet another LSPV/ABS delete how to... - https://forum.ih8mud.com/threads/yet-another-lspv-abs-delete-how-to.930378/
 
I'm not sure if I am talking to myself or if anyone else is reading. I don't mind talking to myself.

Today I spent my time plugging off the master cylinder. When I disconnected the front brakes and plugged up that supply, the pedal felt solid. Then I disconnected the rear brakes supply too, so that both supply ports where plugged. It felt super solid. So I am confident that my master cylinder is good. I then reconnected the front brakes. I don't think I introduced a bubble, because the meniscus was still at the flare of the tube. When I reconnected the fronts, It felt solid too.

This is where I am confused, with the fronts disconnected and rear connected it felt solid, which should lead me to think the issue is in the front.

With the rear disconnected and front connected it felt solid, which should lead me to think the issue is in the rear.

The only thing I am confident about is that my master is good.

I then spent the day replacing the single flares I had made with double flare. My goodness, that was harder than I thought it would have been. I got too good flares and 7 duds that I had to cut off and flare again.

I used this tool:

https://www.northerntool.com/shop/t...-dnrR2kQHt0EzxBxJKRoCcLcQAvD_BwE&gclsrc=aw.ds


I wish I had bought this tool:

Amazon product ASIN B06XPRVCPV
But so far, no leaks.
 
I'm not sure if I am talking to myself or if anyone else is reading. I don't mind talking to myself.

Today I spent my time plugging off the master cylinder. When I disconnected the front brakes and plugged up that supply, the pedal felt solid. Then I disconnected the rear brakes supply too, so that both supply ports where plugged. It felt super solid. So I am confident that my master cylinder is good. I then reconnected the front brakes. I don't think I introduced a bubble, because the meniscus was still at the flare of the tube. When I reconnected the fronts, It felt solid too.

This is where I am confused, with the fronts disconnected and rear connected it felt solid, which should lead me to think the issue is in the front.

With the rear disconnected and front connected it felt solid, which should lead me to think the issue is in the rear.

The only thing I am confident about is that my master is good.

I then spent the day replacing the single flares I had made with double flare. My goodness, that was harder than I thought it would have been. I got too good flares and 7 duds that I had to cut off and flare again.

I used this tool:

https://www.northerntool.com/shop/tools/product_200806235_200806235?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Hand Tools > Tap + Die Sets&utm_campaign=Wilmar&utm_content=9094039&gclid=CjwKCAiApNSABhAlEiwANuR9YIQe2j8XbFzJgI2LraNvGyi9RNeT6INu5Xt-dnrR2kQHt0EzxBxJKRoCcLcQAvD_BwE&gclsrc=aw.ds


I wish I had bought this tool:

Amazon product ASIN B06XPRVCPV
But so far, no leaks.
Nice talking to you Thursday night, wish I knew the answer to your problem but maybe someone else will jump in with a possible solution.
 
Thank you @McDowra, I think it is mostly working through all the possibilities. I bleed the brakes again today, this time I used twice the amount of fluid I normally would. It seems tighter than before. It certainly took more force to get the pedal to touch the ground. Tomorrow I will try adjusting the plunger between the vacuum boost and the master Cylinder.

Is there a good way to judge the length of the plunger? Is it just trial and error?
 
The adjustment worked a little. The brake feels like if I had just a couple more inches of travel the pedal would stop.

I am going to take off each of the banjo bolts and bolt up each banjo with a normal bolt and crush washers to make it sealed off. . This should help me eliminate an issues with a caliper.
 
Get it figured out yet?
 
Get it figured out yet?

Last night I convinced my wife to go out and help me after the kids went to bed. We tried the pressure bleeder and pumping the brakes per this thread:


I was surprised that more bubbles came out. The brake pedal felt stiffer, but when I turned on the car you could still get it to touch the floor. I doesn't feel like it is sinking, it feels like it is traveling and then run out of room. It also feels like if I had another inch of travel it would stop.

I'm running out of ideas and I need to take it to someone to fix it for me.
 

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