With & Without Brakes

[JASTECH]

Howdy! Longtime since I've been on here, work accident put me in ICU, became disabled, then my wife abandoned my son and I. Do to health issues we had to move to a warmer state. Now your up to par, Lol
1988 F-350 7.3 idi XLT Lariat
I had work done before the move so we'd be OK. Now, brakes are hard at times, sometimes soft and if held will go down. Before the move i had Goodyear flush brakes and put Amsoil in. A guy shipped me his used vacuum pump? Before we had moved, it worked, now this. Had trailer brake controller installed, sending units in both tanks and heavy duty hitch for the trip. Now Rear Antilock brake light stays on. I had Diesel mechanic change return lines, mine were the original grey. Was sent a kit to upgrade to 5/16, mech didn't like the braided hose so he put regular hose on. Its leaking on manifold, hard starting, will not start when cold. Noticed a glob of silicone on top of fuel filter bracket holding a wire? My best friend passed away, his wife wants me to have some of his treasures, so this will be a drive across 3 states with my son. TIA

 

[franklin2]

Brakes being hard is a sign of no vacuum. If you pump the brakes on these trucks, it's not very difficult to use up the vacuum and the pedal will get hard. Since you have been messing with the vacuum pump, I would look there. Also look at the main vacuum line leaving the pump. They ran it around the pass side inner fender, and it likes to rub from the engine shaking. I have seen them rub through a little hole in this line, and that is a big leak in the main supply line.

The pedal sinking is usually a sign of a bad master cylinder.

The regular hose on the return lines is ok, as long as it's fuel rated hose. Even then, some of this hose made in China is not very good, even if it does say "fuel" on the hose.

By now, I am not sure any of these early anti-lock brake systems are still functioning correctly. When you get the time, bypass the valve on the frame and drive on.

 

[JASTECH]

Can I check with vacuum gauge? Its what I used on carbs many years ago.

 

[gnathv]

Yes you can. Should read in green or better.

 

[tradergem]

The glob of silicone holding a wire on top of the fuel filter could be sealing a air leak in the fuel heater connection.

 

[IDIBRONCO]

Can I check with vacuum gauge?

I installed a vacuum gauge in my Blue Truck so that I can monitor the inches of vacuum from the pump. I will do this in every IDI powered truck that I own from now on. I highly recommend it because you can see the health of your vacuum pump at a glance.

 

[JASTECH]

I installed a vacuum gauge in my Blue Truck so that I can monitor the inches of vacuum from the pump. I will do this in every IDI powered truck that I own from now on. I highly recommend it because you can see the health of your vacuum pump at a glance.

What gauge and where did you connect it?

 

[IDIBRONCO]

I don't remember the brand. It wasn't a really high quality gauge. I just found a place in the vacuum lines to connect it to. You could probably even use a T in a vacuum line to connect the gauge.

 

[JASTECH]

Yes you can. Should read in green or better.

Where do I connect it to test vacuum pump? That's a rather big hose on pump compared to vacuum lines on gas engine.

 

[JASTECH]

Oh, OK, so "any" vacuum line is OK to test pump?

 

[tradergem]

The vacuum line from the pump should connect to a distribution tee on the fire wall that all of the other vacuum lines connected to the tee. I connected my vacuum gauge to this distribution tee and by plugging and unplugging the other vacuum lines to the tee I was able to isolate any parts of the vacuum system that had any leaks, including the pump itself.

 

[IDIBRONCO]

Oh, OK, so "any" vacuum line is OK to test pump?

The vacuum line from the pump should connect to a distribution tee on the fire wall that all of the other vacuum lines connected to the tee.

I'm not any type of expert on this, but here's my opinion. You can use any vacuum line to test your pump/install a gauge. The tee that tradergerm mention would probably be the "best" place to attach a gauge. It's the easiest place to attach to that is "direct" from the pump. It's kind of like attaching the feed for an oil pressure gauge down low, close to the filter to show the highest oil pressure. This tee should show the best vacuum reading and be the place that recovers from using the brakes first. Not that there's a big difference, but it's pretty close to the source of vacuum.

 

[quickster]

Thanks for posting this info guys. I need to check the vacuum, and putting in a gauge sounds like it would be a good asset. My brake pedal is hard also.

 

[IDIBRONCO]

putting in a gauge sounds like it would be a good asset.

I feel that it should rank right up there with a pyrometer. If you've ever had one go out while driving down the highway, you realize it's importance. It may not be as important if you have hydro boost brakes though.

 

[JASTECH]

I will test with my vacuum gauge tomorrow then report back the findings. I'd pressure wash the engine but someone stole mine from next to my house. I've had animals stolen, poisoned and shot, let alone all the theft.