Serious Transmission Leak On My M1009

[niferous]

Ok I got my driveshaft today and got it in the truck as soon as I got home. Well I get in and start the truck up excited to take it for my first spin in this truck. Well it started right up (generator 2 light still on) and tried to put back out of the garage. NOTHING. Truck wouldn't move back. So I put it in drive and still nothing. I put the truck in park and get out to take a look underneath to see if anything looked a miss and it sure was! There was a huge puddle of transmission fluid underneat the truck. I turned it off and got on my creeper to try and at least see which side of the trans the leak was coming from and it looks like the drivers side. It's only leaking when the truck is running though. I'm going to try and jack the truck up here in a little bit and see if I can't find more specifically and take sone pictures for you experts. Is there are anything I should look for or can you guys guess what the culpit may be?

 

[84cucv1ton]

on mine the cooler lines had leak

 

[ralbelt]

mine had the cooling lines disconnected.they are on the passanger side I don't remember any connections on the drivers side excet the shift lever.

 

[niferous]

Ok I found it. This is on the right (passenger) side of the trans. Not sure what they are as I'm no trans expert although whatever is missing it looks like it just screws into the side of the trans. Hopefully this is something I can get locally so i can drive it this weekend!

 

[niferous]

Looking around on the net I think it's the vacuum modulator. Infact I'm sure it's the vacuum modulator. Can anyone give me the part number for one? All I have been able to find is the B&M Part number and the local guys can't find it in their catalog.

Edit to add: I found one by going on the O'Reilly website and searching for one for a Chevrolet 1-ton. Came up that way. However I don't know if it will come with the little bracket that the screws slides through and secures it to the trans. Any help is much appreciated guys since I'm so anxious to get this thing driving!

 

[ralbelt]

I got mine at Napa. Parts guy had no problem finding it, I might still have the # at work, i.ll check tomorrow,

did not come with bracket

 

[niferous]

So where is the best place to get the bracket?

 

[ralbelt]

I would think a junk yard or dealer. should be about the same on most GM trucks of same vintage

 

[12vctd]

Wheres the braket that came with it? or was it missing already? Either way the fastest place to find a braket will be a junkyard all th400's will have it 2wd and 4wd. PATC and many transmission parts places will also have but you most likely will have to order the part.

 

[ralbelt]

should be able to fab one out of 1/4 in flat stock ,notch one end to fit modulator and drill a hole as required.

 

[niferous]

I'll probably try to find an open junk yard tomorrow and get one.

 

[Bobert]

I got a modulator a couple weeks ago, Advance had one for $12, Oreillys was $29.

Advance part number MD48. Works just fine.

 

[niferous]

Anyone know what size bolt it uses in case have to fab one?

 

[91W350]

Swing by your local transmission shop, that is something they probably have in parts buckets. I know our local guy has several 400 cores.

 

[ralbelt]

Napa # is either 904711 or 1-7499 both #'s are on the box. The bolt as I remember is either 1/4 0r 5/16 course thread about 1" long should do it.

 

[Peepaw]

It's hard to tell from the picture, but is the actual valve in the trans.
There should be a valve in the trans case that the vacuum modulator valve acts on. Without the inner valve it's not going to work.

The valve in the trans is a couple inches long. Then the vacuum modulator rides on the end of that valve and works it according to vacuum levels (load).

 

[niferous]

Yeah it looks like it is missing. Wasn't sure so I went and installed the vacuum modulator and the truck still does not move. So does anyone know the technical name so I can look it up at the auto parts store website? Or does anyone just know the part number for it? Is it part of the valve body?

 

[niferous]

Ok I found a schematic and may have an idea what I'm looking for. Is the part I have the arrow pointing to in red what I am looking for?

 

[Peepaw]

I believe the steel valve is the actual modulator valve. If there is a transmission shop nearby, you could probably get one from them.
Most parts houses like Napa, etc won't carry the actual valve.

 

[niferous]

Thanks Peepaw I was afraid that would be the case. I will probably have to wait until Monday and call. I got the bracket from Apache Transmission Parts here in Houston for $5 with the machine screw. Unfortunately they are only open until noon on Saturday. I'm sure they will have the valve too but I was hoping it would be as common as the vacuum modulator so I could get it this weekend and get the thing moving!

Isn't there supposed to be a spring in there as well.