3.0 loss of vacuum

[El Toro]

Just wondering if this happened to anyone else. Yesterday I started my Ford Ranger 3.0L and it started fine. After I pulled out of my driveway I had no brakes at all. So I pulled back into the driveway and went under the truck as it sounded like I had an exhaust leak. Couldn't find anything obvious so I got back into the truck and it was idling rather rough. After about 5 minutes it smoothed out and my brakes came back. I seemed to experience a total loss of vacuum and I'm not sure where to start my investigation. Now I've heard of vacuum leaks causing rough idling but never enough to cause my brake booster to fail. Any suggestions? Thanks

 

[franklin2]

Get some vise grips and carry them with you in the truck. The next time it happens, take them and pinch the rubber vacuum line shut that goes to the booster. If the engine smooths out, I would suspect the booster has a problem.

If the engine is running, you should have some brake booster action. If you had no vacuum at all at idle, the engine would stall.

 

[2011Supercab]

Had no brakes or had no power brakes?

Pedal went to floor or couldn't push pedal at all?

 

[El Toro]

Had no brakes or had no power brakes?

Pedal went to floor or couldn't push pedal at all?

No power brakes. Pushed pedal all the way to the floor. Very hard push

 

[El Toro]

Get some vise grips and carry them with you in the truck. The next time it happens, take them and pinch the rubber vacuum line shut that goes to the booster. If the engine smooths out, I would suspect the booster has a problem.

If the engine is running, you should have some brake booster action. If you had no vacuum at all at idle, the engine would stall.

I will. Thanks for the idea.

 

[aldon]

Just wondering if this happened to anyone else. Yesterday I started my Ford Ranger 3.0L and it started fine. After I pulled out of my driveway I had no brakes at all. So I pulled back into the driveway and went under the truck as it sounded like I had an exhaust leak. Couldn't find anything obvious so I got back into the truck and it was idling rather rough. After about 5 minutes it smoothed out and my brakes came back. I seemed to experience a total loss of vacuum and I'm not sure where to start my investigation. Now I've heard of vacuum leaks causing rough idling but never enough to cause my brake booster to fail. Any suggestions? Thanks

EGR stuck open? Or leaking

 

[El Toro]

I have not checked the egr valve. I will do thanks. Could the booster check valve be faulty?

 

[Wahoo]

Just wondering if this happened to anyone else. Yesterday I started my Ford Ranger 3.0L and it started fine. After I pulled out of my driveway I had no brakes at all. So I pulled back into the driveway and went under the truck as it sounded like I had an exhaust leak. Couldn't find anything obvious so I got back into the truck and it was idling rather rough. After about 5 minutes it smoothed out and my brakes came back. I seemed to experience a total loss of vacuum and I'm not sure where to start my investigation. Now I've heard of vacuum leaks causing rough idling but never enough to cause my brake booster to fail. Any suggestions? Thanks

I recently had a vacuum leak too, didn't affect brakes. The leak was at the passenger side firewall. A firm vacuum line that went to a black reservoir, mounted on ac equipment piece. The vacuum line just made a hard U turn into black reservoir. (Not sure what it is for or does) but the just I'm getting to is there are a lot of vacuum lines that feed off main vacuum sources, so check any vacuum line you see. Also on drivers side there is a knob of vacuum nipples, some used some capped. Visually check and maybe spray areas with carb cleaner see if RPM change for leak.

If anyone knows what black reservoir on firewall , passenger side is for , I'd appreciate info.

Thx wahoo

 

[franklin2]

The vacuum reservoir is to give all the vacuum devices a supply of vacuum when the engine is pulling a long hill. Vacuum is only developed by the throttle being partially closed. When you open the throttle up to get some power, there is no vacuum being generated by the engine. So there is a check valve in the main line to the reservoir that isolates the engine during low vacuum events, and the vacuum devices can still get a supply from the reservoir till the throttle closes back and starts supplying vacuum again.

This situation is worse with small engines, so much so that some small cars actually have a electric vacuum pump.

 

[Wahoo]

Ok, that would make some sence, I never looked for a check valve, do you know where it's located in vacuum line? Picture of check valve?
There was a short section of Ridged vacuum line missing so I never saw this vacuum line stock to know if I'm missing a part.

Thx for insight

 

[franklin2]

I varied by different years and different models, but sometimes the check was made right into the inlet of the reservoir.

 

[Wahoo]

Ok, thx I'll look into that .
Appreciate the info

 

[Wahoo]

So now that I kinda know what it's called . I did some more research. It's a vacuum resivor for the AC system. The lines are all kinda treed of a main vacuum line so it did affect vacuum to the other sensors and egr system. Leak plugged no matter what , so all is good for now. Fixed drive ability, smoother, and it's a work in progress