ayoung101

so something is definitely wrong with my truck. i hit the brakes and heard a pop. the brake pedal went to the floor with no braking power. i was able to pump up the brakes and get some brake pressure, but i could definitely feel fluid leaking. so i limped it home and into the garage. 5 minutes later i had a 2 ft diameter puddle of black fluid under the engine. i WOULD think it's oil, but i just changed the oil less than 15 miles ago, and the oil on the dipstick isn't even black yet. front diff maybe? a bit behind there, i'm leaking a bit of fluid from around the bell housing (csc?). and way in the back, just in front of my tire i'm leaking break fluid.

WTF could have possible made all this happen?!?!?!? up to this point, i've never had a problem with anything. no leaks, no strange noises, no nothing. i really need some help here, because my only "spare" vehicle is my motorcycle. i don't know if i should (or even can) fix it, i don't know if i should just start scrapping it out, or if i should just have it towed away to RIP (Rust In Peace).

anyone need a project truck? any idea approx how much i could get from piecing it out onto yotatech?

jason191918

Whoa, Slow Down.

Find out why the brake fluid is leaking and find out what the other fluid is. Then check back.

gilby4runner

like he said... find out what it is first. You will be able to tell if its gear oil by the smell. (Easiest way to tell). Get up under it and check to see where it is all coming from. Check your brake fluid reservoir and see how much fluid is in it.

ayoung101

now that it's saturday i have a little more time to look at things. i absolutely guaranteed have a break leak near my rear wheel in the line above the gas tank (SUCK). i had my wife pump the brake pedal and it just poured out until she stopped. so that one sucks and i'm not quite sure the best way to fix it yet.

the other mystery fluid doesn't appear to be a mystery anymore. i would say it's definitely engine oil, i just don't know where from. i'd say it's either from the oil pan, or from this "thingy" slightly above it (see picture). i have no idea what the "thingy" is. (which is where all you come in). with the engine running the fluid constantly drips from the oil pan lip right beneath the "thingy", but i can't tell if it is coming from the oil pan lip or above at the "thingy". the "thingy" has visible threads, as you can see. i'm assuming this is not normal to see these threads. what is it? after the engine cools down i can go play with it and try to re-screw it in.

jason191918

As for the break line, it is either the return or supply for the LSPV. I had one of these go out last week. Inside the frame rail you will see 3 lines. 2 are the mentioned break lines and the larger one is the supply gas line. Both break lines end at the LSPV in the back. In the front, one goes to the actuator for abs (i think) and the other goes to a T right behind the FR tire (this was the one i had to fix). Because I did not feel like dropping the fuel tank in my gravel driveway, I cut the line on each side of the fuel tank, then ran the brake line on top of the frame rail where the fuel tank is, and inside the frame rail in front of the fuel tank (where the line was originally).

ayoung101

1st, i hope this isn't a stupid question, but what is the "LSPV"?

and are you saying you instead of dropping the gas tank to replace the line to the rear wheel, you just ran a new line in an area that was convenient for you? i'm a little confused as to what you did. you don't happen to have pictures, do you?

(also, i don't have ABS)

jason191918

LSPV=Load Sensing Proportioning Valve. I would imagine your truck has it. It is valve mounted on the frame on the passenger side. There are 3 brake lines and one bleeder threaded in it, as well as a rod. This rod is bolted to the axle. As the load in the rear changes, it changes the front/rear brake bias. For instance, if you load the bed with women, the rear brakes will get more pressure, On the other hand, if you have no friends, the front brakes will get more pressure. One of the brake lines goes the the rear and gets split for right and left rear brakes. Another line is the supple, which I would guess goes to the Master Cylinder (because you don't have ABS). The other line is the return (for when there is less pressure needed in the back) which I would think still goes to a T in the front right.

Yes I did just put the line where it was convenient.

I don't have any pictures, but I can take some. What would you like to see?

ayoung101

LOL

i've never heard of an LSPV before. can you take a picture of it so i know what i'm looking at? i'm sure i've seen it but just haven't known what it is. also, you said you had to change the line in the front? if so, i don't think that wouldn't help me much to see a picture of how you ran those lines.

so, above the gas tank, there are THREE lines? any idea how to figure out which one has the leak, since they are impossible to see?

jason191918

http://www.ncttora.com/fsm/1990-1995...r/loadsens.pdf

Here is a picture of the LSBV, as well as more details as to how it works.

The lines that are between the frame and the fuel tank end at the LSPV and the front of the truck. That is why I said the line is in the front.

As for finding the leak, maybe unscrew the 2 lines the go forward from the LSPV and see which one has fluid in it? I do know the the line that is on top when it disappears behind the tank (from the back of the truck), is the same line that is on top when they are against the frame (in the middle).

ayoung101

any help on this?

jason191918

Did you fix the brake problem?

abecedarian

oil pressure sending unit? and don't tighten it down too far- the threads on it are tapered and will cause the passage in the block to crack if it's tightened all the way down.
judging by the oil all over, I'd lean towards the front crank seal.

ayoung101

no, but i didn't try either. haha, it was too nice today. went out on my buddy's boat instead. haha. hopefully i'll make some progress in the coming week.

it could be a oil pressure sensor/oil sending unit. now that i narrowed it down to a close area, i'll just get the dye if i can't figure out exactly where it's coming from. i'm really hoping it's from this sensor (or whatever it is) and not the oil pan. the sensor would be a wee bit easier to change, haha.

jason191918

Are there any wires coming out of it? If it was the sensor, there would be wires coming out, but I did not see any in the picture.

ayoung101

yes, there are wires coming out of it. i think 2, but i'm not sure.

ayoung101

i was wrong, it is only a single wire sensor. any idea what it is?

a4runnerfreak

It's your oil pressure sending unit, like Abe said.

ayoung101

so would it be a HORRIBLE idea to completely bypass the LSPV? my brake lines are rusted solid to it, there's no way they are coming off. i tried heat, i tried PB blaster, and with either an open end wrench OR a vise grips, the edges just round off. i gotta get this thing fixed. i only use it a few months out of the year, and ONLY to commute 20 miles round trip (and the occasional offroading trip). is it possible to just omit it, have 1 brake line split to the front, and 1 brake line split to the rears, and be done with it?