Vacuum pump output

[asmith]

So I think my vacuum pump went out. yesterday coming home from work, my brake pedal became rock hard. pushing as hard as I could against the pedal really did nothing to slow the truck. even going slow enough to not register on the speedo it takes me 20 ft to stop with me pushing for all I'm worth. Rolled through a stop sign at 40mph because I couldn't stop in time the first time I went to stop. Praise God no one was there. limped it home going real slow and basically standing on the brake pedal a mile ahead of time. I pulled the hose from the pump to the vacuum manifold, and ran it strait to the booster. no change. so this leaves the booster and pump. I pulled the hose off with the engine running and even though it is not a perfectly even cut across the hose, it is not that off and the pump will not hold a piece of paper to the hose. that seems to weak to me. I don't have a gauge to measure the vacuum, but is there a relative pull I should be seeing?

PS I am on the hunt for hydroboost stuff, but there are none in the yards around me. So if anyone has hydroboost stuff for sale let me know. Also I will be swapping my truck over to manual sooner rather than later, so if you have manual pedals for the hydroboost that is what I am looking for.

 

[riotwarrior]

Sounds like a pump to me.

 

[OLDBULL8]

Holding your finger over the end of the hose it should almost suck the blood out of your finger. If you have the tomato can (vacuum reservoir) on the drivers side fender it may have rusted a hole in it, if so, you loose all vacuum, check it out.

 

[Thewespaul]

Its the pump! had the same experience earlier this week, if it happens again use your e brake to stop or go to neutral and rev the engine up, even with a bad pump it will create enough vacuum to stop

 

[asmith]

Thanks for the replies. Bought a pump, got the old one off, new pump does not have a pulley on it, should have checked while I was in town. call around everyone has their loaner tools out right now. took it to a shop to get the pulley swapped over. should have it done in a couple hours. we will see.

oldbull thanks for the pictures. mine is a '93 and does not look like that. I think someone has messed with it in the past. I do not have a vacuum reserve can at all. also i do not have a vacuum line going to the transmission, I think that is only for the C6 right? I have the E4OD. My vacuum pump is on top of the engine on the drivers side and lastly the manifold is on the drivers side fender not on the firewall. I think while I am doing all this I will try and replace the old brittle vacuum lines too.

Different note. I noticed my belt is really worn out and I need a new one, the routing looks wrong to me (have not messed with it since I bought the truck) any one have a picture of the correct routing for a 7.3NA with AC?

 

[madpogue]

E in E4OD means Electronic, so correct, no vacuum feed to the transmission.

No belt routing sticker on the rad support? What looks not right about it?

 

[asmith]

Got the pump back yesterday afternoon with the pulley put on. came back put it on and hooked it strait up to the vacuum booster again. went for a test drive. ALL GOOD!! came back hooked it up to the manifold and everything is as it should be. Thanks for the help guys. glad to have it back.

I have a sticker on the core support, but it does not match my engine. all of the accesories are in different locations than the sticker shows

I will get a picture of the belt routing on there now, but the belt is incredibly tight, and doesn't seem to loop around the water pump enough to me. maybe it does, just doesn't seem like it.

 

[madpogue]

Post pics of the routing sticker and of your accessories.