Hungry Valley trip and the things I learned (1 Viewer)

[alia176]

I have nothing new to contribute except, is THAT your ugly mug in the pic? You sure the kid is yours?

 

[80t0ylc]

I have had mine stall on steep inclines when I forget to lock the CDL. I was able to stop immediately and there was no harm, I just started it back up and locked the CDL and up the hill I went.

My 80 and it sounds like yours do not like loosing traction on inclines with the CDL unlocked, mine doesn't stall everytime, but it has happened a few times. I have never had a problem with the CDL locked, so if you are going to be climbing anything I would recommmend locking the CDL.


Jack

Here is the 1st clue. Jack's is a '96, yours is a '97. Could it be something with the OBII setup? Both of you were CDL unlocked. Christo has excellent point while climbing. Viewing hill and pucker factor & the coward that I am, I know I would have had CDL locked - that's NOT just Monday Morning Quarterbacking talking, either. NLXTACY, you need to go back to that hill and try it again with CDL locked, AFTER you install your sliders, eh!

 

[jonheld]

And B it should not then have thrown everything into "neutral" allowing me to go barelling backwards down the trail.

Actually that's exactly what should have happened. An auto transmission is controlled by fluid pressure. The pump is the input shaft. When the motor stalls there is no more fluid pressure and it all freewheels.

FWIW I have almost stalled my truck by letting it roll backwards while in a forward gear. I have never had any issues with inclines.

 

[george_tlc]

Try to let your 80 roll backwards (in drive) on a STEEP enough incline, I'm am pretty sure it will stall. I have a 97. I'm not talking rolling backwards a foot, I'm talking the heat of the moment, 80 is spinning tyres and before you have a clue of why, you back off the skinny pedal, it rolls back several feet and it stalls. Do this somewhere safe and the incline is short. I've been in my 80 and I've seen this happen.

I'm guessing that since you had the CDL unlocked, your wheels started spinning, you backed off the skinny pedal to try and get traction back, the 80 started rolling backwards, the engine stalled out, auto has no pressure, brakes have no power boost and you're off on toads wild ride...

cheers,
george.

 

[Brentbba]

Gotta love the pic of you and your sliders. Mine looked exactly the same after my first visit to Miller's Jeep trail...and I took them off before the wife saw them too!!!

 

[Beowulf]

First time I stood on the brakes and nothing. Second time it seemed like I was going even faster and I was pumping like a mad man. Nothing at all. It was the brush that stopped me.

Don't you have an e-brake?

There have been a couple of reports where a new fuel filter resolved problems with stalling on steep inclines. Junk was one of those reports a few years ago. The brake booster should have enough stored vacuum to stop the vehicle when the engine stalls. A few weeks ago, a friend with a '94 stalled at the top of a steep obstacle. We were playing in the rocks so not quite the same as your flat trail but his brakes held just fine even with the engine not running.

Peddle pressure increases dramatically without vacuum boost but I still think you should be able to stop the truck. I could be wrong.

-B-

 

[NLXTACY]

Well that answers half of part one. CDL ALWAYS from now on. But why stall? And why ZERO brakes. Pump or no pump, brakes gone.

Don't do hill climbs with CDL off. It will act as an open diff. If you loose traction or unload the front, then nothing is going to keep the back axle from holding you in place. Did you try the hill with CDL locked?

Why truck stalled, I do not know.

I have had mine stall on steep inclines when I forget to lock the CDL. I was able to stop immediately and there was no harm, I just started it back up and locked the CDL and up the hill I went.

My 80 and it sounds like yours do not like loosing traction on inclines with the CDL unlocked, mine doesn't stall everytime, but it has happened a few times. I have never had a problem with the CDL locked, so if you are going to be climbing anything I would recommmend locking the CDL.


Jack

 

[NLXTACY]

I have nothing new to contribute except, is THAT your ugly mug in the pic? You sure the kid is yours?

Yeah its my face only a mom could love.

And to be honest, I really don't want to know if he isn't mine. Ignorance is bliss

 

[NLXTACY]

Well I will tell you that this was definitely a learning experience. Normally I always have CDL on but this time just plain forgot. So its good to actually KNOW for sure what happens when CDL is off. No anecdotal evidence here

Here is the 1st clue. Jack's is a '96, yours is a '97. Could it be something with the OBII setup? Both of you were CDL unlocked. Christo has excellent point while climbing. Viewing hill and pucker factor & the coward that I am, I know I would have had CDL locked - that's NOT just Monday Morning Quarterbacking talking, either. NLXTACY, you need to go back to that hill and try it again with CDL locked, AFTER you install your sliders, eh!

 

[NLXTACY]

I'm guessing that since you had the CDL unlocked, your wheels started spinning, you backed off the skinny pedal to try and get traction back, the 80 started rolling backwards, the engine stalled out, auto has no pressure, brakes have no power boost and you're off on toads wild ride...

cheers,
george.

The first time yes BUT the second time I was throttling it to keep fuel going thinking it was just cutting out and bam, same result.

 

[NLXTACY]

Yes I have an e-brake

And no I didn't use it

I was too busy keeping both hands on the wheel, eyes locked on the mirror and all of my weight on the brake peddle.

Fuel filter was changed less than 2 months ago so I would like to say that wasn't it but who knows.

And yes I agree my brakes should still have worked regardless of vacuum. But nothing. And after the incident everything was fine, no issues at all. Brakes worked fine, engine ran normal. No problems. Except for the power steering fluid spilling out of t he reservoir.

Don't you have an e-brake?

There have been a couple of reports where a new fuel filter resolved problems with stalling on steep inclines. Junk was one of those reports a few years ago. The brake booster should have enough stored vacuum to stop the vehicle when the engine stalls. A few weeks ago, a friend with a '94 stalled at the top of a steep obstacle. We were playing in the rocks so not quite the same as your flat trail but his brakes held just fine even with the engine not running.

Peddle pressure increases dramatically without vacuum boost but I still think you should be able to stop the truck. I could be wrong.

-B-

 

[Atticus]

Are you sure you were rolling and not sliding? Could you have locked your brakes and slid down the hill?

 

[NLXTACY]

Are you sure you were rolling and not sliding? Could you have locked your brakes and slid down the hill?

Tires lost traction for ONE second at the very top then the truck literally rolled. 100% rolled and didn't slide down. When I say I tried to use the brakes, I TRIED. I had all 200# of me standing on the brakes which did nothing and then tried pumping like a mad man and zero. I had my kid and dog in the truck and all I kept telling myself is NOT to roll the truck so thats why I was focusing on staying straight and trying to bend the brake pedal. If I was sliding it would have been a slower decent. I was in free fall and GAINING speed.

It was seriously freaky and especially the second time scared the SH!T out of me.

 

[Atticus]

Tires lost traction for ONE second at the very top then the truck literally rolled. 100% rolled and didn't slide down. When I say I tried to use the brakes, I TRIED. I had all 200# of me standing on the brakes which did nothing and then tried pumping like a mad man and zero. I had my kid and dog in the truck and all I kept telling myself is NOT to roll the truck so thats why I was focusing on staying straight and trying to bend the brake pedal. If I was sliding it would have been a slower decent. I was in free fall and GAINING speed.

It was seriously freaky and especially the second time scared the SH!T out of me.

I imagine it was very scary, especially with the kid in the car.

I think it's really bizarre that you had NO brakes, even without power assist. I've lost power before, but when you really stand on the brakes, they bite. Do you have any other problems with your brakes?

 

[NLXTACY]

I imagine it was very scary, especially with the kid in the car.

I think it's really bizarre that you had NO brakes, even without power assist. I've lost power before, but when you really stand on the brakes, they bite. Do you have any other problems with your brakes?

That's just it, I've also been in situations where truck is off and I was still able to stop. Once intentional to KNOW what happens and the second time it was my wife driving and she stopped fine.

Brakes have been fine and I've never, up to this point, had issues. My brakes are less than 2000 miles old and I am using 100 series pads. No pulling now, no issues and the reservoir is full.

 

[Nemo]

I have only had this happen once with my 97 LC. We (Girlfriend and me) were on Slaughterhouse Gulch in CO when I decided to let the GF drive for a poser shot (those that have done this trail knows where I am talking about) where the terrain makes for a perfect hi-Wheel stand but safely. She got in and got scared and stopped and it rolled back just so slightly and it stalled.

So I am sure you "can" stall it but I have never done so myself. Steady on the Gas and away I go. In 4LOW CDL locked as well as front & rear diff. GF was driving.

She hit the brakes and it stopped without issue. I would state that something is wrong with you brakes for sure. You mention not having them so would a Vacuum leak make for it to be worse on the accent and descent. Meaning Vacuum leak causing "premature" stall and Vacuum leak causing "no brakes"?

I have used my brakes even after not starting the engine. Say I needed to just move it down a small hill et al., and instead of cranking, I just put it in neutral and away I went "short distance" and then hit the brakes and stopped. Check you brakes for leaks and Vacuum....;p

 

[Beowulf]

I was in free fall and GAINING speed.

There is something amiss with your braking system and I would not put myself or my family in that position again until it was resolved. On most systems, there is a check valve in the power brake booster. I don't have the FSM handy but check yours to see how this works on the Toyota system.

"Vacuum boosters also have an external one-way check valve at the hose inlet that closes when the engine is either shut off or stalls. This traps vacuum inside the booster so it can still provide one or two power assisted stops until the engine is restarted. The valve also helps maintain vacuum when intake vacuum is low (when the engine is under load or is running at wide open throttle). You can check the valve by removing it and trying to blow through it from both sides. It should pass air from the rear but not from the front."

And get familiar with your e-brake, make sure it is 100% operational, and practice using it on steep obstacles.

-B-

 

[uberhahn]

your braking issue sounds like a vacuum/pressure loss (not to be obvious). Engine off braking performance should remain same for at least 10 vehicle stops - there should be enough vacuum in the system to assist braking.

is it possible for you to replicate the failure on level surface with engine off? if your cap/lid wasn't tight, or if the seal around it somehow failed, all vacuum would be lost.

would be good if you could replicate the failure and go from there.

 

[NLXTACY]

Totally agree and we didn't do anything after that but go to the creek and then head home.

I will check out the vacuum hose and check valve tonight.

There is something amiss with your braking system and I would not put myself or my family in that position again until it was resolved. On most systems, there is a check valve in the power brake booster. I don't have the FSM handy but check yours to see how this works on the Toyota system.

"Vacuum boosters also have an external one-way check valve at the hose inlet that closes when the engine is either shut off or stalls. This traps vacuum inside the booster so it can still provide one or two power assisted stops until the engine is restarted. The valve also helps maintain vacuum when intake vacuum is low (when the engine is under load or is running at wide open throttle). You can check the valve by removing it and trying to blow through it from both sides. It should pass air from the rear but not from the front."

-B-

 

[NLXTACY]

Well only way to replicate would be to find another incline but all the inclines around me have homes on them and no way I want to risk that. I will be following the FSM tonight to check everything.

The curious thing is regardless of vacuum, say there is zero, shouldn't the truck still stop regardless of there being vacuum or not?

your braking issue sounds like a vacuum/pressure loss (not to be obvious). Engine off braking performance should remain same for at least 10 vehicle stops - there should be enough vacuum in the system to assist braking.

is it possible for you to replicate the failure on level surface with engine off? if your cap/lid wasn't tight, or if the seal around it somehow failed, all vacuum would be lost.

would be good if you could replicate the failure and go from there.