name this part

[AZBLACKSMOKE]

Anyone know what this is and what it does? The little thingy with a vacuum line and electrical plug that sits northwest of the GP relay. Does it have to do with the cruise control? Its on an 86 f250 6.9, t-19.

I am waiting for my factory service manual to arrive but the suspence was killing me. Thanks.

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[91idi]

Its a low vaccume switch.

 

[AZBLACKSMOKE]

Its a low vaccume switch.

Thanks. What does it do excactly?

 

[91idi]

Just turns on your brake light on your dash to let you know its low. This lets you know your brake booster is not going to work,making the pedal hard and brakes not work

 

[icanfixall]

Yes... Thats what it is but.... When you loose your vacuum a dash lite comes on telling you... Low Vacuum..... Hopefully you can stop the truck when you see this. Usually its way too late when you see this. When its happened to me I "found it" when I hit the brakes only to find a million pounds was needed to push the brake peddle. But steady pressure will slow you down. Find a country road and remove the vacuum pump belt and drive slowly and try to stop. This will give you a feel of just how hard it is to stop these rigs without vacuum assist brakes. Change to hydroboost brakeing and you double your line pressure cutting the peddle effort in half to stop these rigs....

 

[91idi]

Yes... Thats what it is but.... When you loose your vacuum a dash lite comes on telling you... Low Vacuum..... Hopefully you can stop the truck when you see this. Usually its way too late when you see this. When its happened to me I "found it" when I hit the brakes only to find a million pounds was needed to push the brake peddle. But steady pressure will slow you down. Find a country road and remove the vacuum pump belt and drive slowly and try to stop. This will give you a feel of just how hard it is to stop these rigs without vacuum assist brakes. Change to hydroboost brakeing and you double your line pressure cutting the peddle effort in half to stop these rigs....

Kind of like i said your brake light comes on because like i said the vaccum was low

 

[91idi]

http://cgi.ebay.com/ebaymotors/94-9...r_Truck_Parts_Accessories&hash=item2ea9fe4108

 

[RLDSL]

What does it do?... Chances are, nothing anymore. Most of the things haven't worked for years. you should test it and if it's not functioning eithr replace or block it off, they are a major potential leak point when old and worn out.

 

[AZBLACKSMOKE]

I

http://cgi.ebay.com/ebaymotors/94-9...r_Truck_Parts_Accessories&hash=item2ea9fe4108

Man, I got lost in that guys eBay store. He's got a lot of good parts.

 

[AZBLACKSMOKE]

Thanks for all the replies. So this thing has nothing whatsoever to do with cruise control, correct?

 

[icanfixall]

Well thats a yes and no answer. No... It wont cause your cruise control to work or not but.... It will tell you that you have lost your vacuum so the cruise control wont work. Vacuum is what makes the cruise open or close the throttle.

 

[AZBLACKSMOKE]

Well thats a yes and no answer. No... It wont cause your cruise control to work or not but.... It will tell you that you have lost your vacuum so the cruise control wont work. Vacuum is what makes the cruise open or close the throttle.

True that. I guess I meant electrically. But ya'll have answerd my questions. There's a few idi's in the local pick and pull and I was rapin and pilligen them for cruise control parts and wondered if I should grab one of those switches. Now that I know excactly what it is I can choose my parts wisely. Thanks guys.

BTW...if there is anything anyone needs off of one..let me know. There is an 85 and an 83 pickup, and the 83 is fairly complete, the 85 is picked thru pretty good, but there is some good az rust free stuff there. I found a set of bb injectors under the seat of the 85. Gonna get them tested and see how lucky I got. It's next door to work, so I can sneak over and snap pictures anytime. The 83 is a ext. Cab 2x4 with c6. The 85 is a reg cab 4x4 but no motor or trans/transfer case. The 83 supposedly has a great running 6.9 and looks complete. Drove in there without reverse. It's now missing front seat and steering column. Anyway, let me know if anyone wants me to go shopping.

 

[oldmisterbill]

If no one wants it I do.Since it was found by a member I won't buy it if he wants it.

 

[RLDSL]

Thanks for all the replies. So this thing has nothing whatsoever to do with cruise control, correct?

Actually, it can, if the thing is leaking like a sieve like mine was, your cruise won't function ( and your brake pedal will get a bit hard, also ac/heater controlls will act buggy)