78 Camper Backfiring Low Power

[Amskeptic]

okay ready here is my rookie diagnosis:

Today I went purchased a new check valve intalled. And immediately it failed. I took a peek at it and there is oil in the vacuum line and now in the check valve allowing air flow both directions.

Blame painfully cheap Chinese crap FIRST.

Here is my theory. A few months ago I noticed when I depressed the brake pedal it made a wierd noise. But they work. I am thinking I must be crazy it must of always done that. I went back and forth and told myself you should check that out soon. I don't think its a normal noise.

I think what happened is the master cylinder was going bad, which in turn leaked into the brake booster, which then caused the booster to fail,

Boosters can fail because they feel like it.

I then install new check valve and no leak but no brakes either.
The pedal is hard to depress,
Is it possible to rebuild the brake booster?
And why is it called a servo on some sites?

If a good check valve is installed in the wrong direction, it will give you no brake assist.
A "servo" or "booster" (same deal) should only draw vacuum while you are moving the pedal p-e-d-a-l, then not draw any more vacuum if you hold the pedal stationary.

Start engine. Apply brakes with that p-e-d-a-l thingy. Shut off engine. Pedal should remain stationary. If it slowly pushes back up, it is leaking.
I rebuilt a brake booster once. Hair raising. Look in the Parts Known To Be Acceptable sticky in the Brakes Forum, and you should see a rebuilder listed.
If the master cylinder ius leaking brake fluid, yes, get a new one. The rubber o ring between the master cylinder and the servo/booster is a critical component for no vacuum leaks!
ColinYerDoin FINE

[pdlrofdrms]

I guess what worries me more than the brakes is there is oil in my vacuum line and I have a air release sound when braking.

I ordered a new check valve from Wolfburg West. I will see if its just that dodad.

I am out of time to tinker with the bus until Sunday. At which I will take a apart the booster and the Master Cylinder and report.

Thanks!

[Amskeptic]

I guess what worries me more than the brakes is there is oil in my vacuum line and I have a air release sound when braking.

Do the test I recommended above. If you hear air when applying the brakes, it may be a leaky hose between the engine and the booster.

I am out of time to tinker with the bus until Sunday.
At which I will take a apart the booster and the master cylinder and report.
Thanks!

Slow down. Follow the recommendations on testing the booster so we don't start replacing more than we have to. However, if you see a fluid track between the master cylinder and the booster (often with blistered paint), then a new master cylinder is pretty much called-for.

The oil in the vacuum line, does it feel/smell like engine oil?
ColinWaitingHereTilSunday

[pdlrofdrms]

Well I crawled under the old gal today after derby practice and guess what!

That dill hole that put in my floor. He melted the hose from the brakes to he brake booster annnnd the braided hose that went to now melted hard plastic hose.. pinched between the new frame and the new floor!

HOLY SMOKES!
Monday I will replace the hoses if I can find some locally.
We actually have a place called applied technology that specializes in vacuum line.

I will have to wait till tomorrow to report back.

DANG! I can not believe I went on back mountain roads in the dark SO DUMB.

[pdlrofdrms]

okay so temp fix on brake booster issue.
got 2ft of heater hose attached to Air connection on the Brake servo? I hope I have that right. Its the fitting next to a rubber boot.

Then I cut the melted part off the plastic hose and connect 3/8 vacuum line from Oriellys to that and clamped it down.
Then had to use a plastic connector I jimmied from a plumbing connector. stuck the 1/2 heater tubing to the 3/8 vacuum line and clamped down.

No more air sound and I have brakes. No hard peddle.

Okay now.
When Airkoooledchris was over. We found that the spark plug wire to number two was bad. These wires are less than two years old. How often do you replace them? I ask because while the car is running better its still lumpy kinda. So I took out my timing lite and now 1 and 3 are missing and not consistently getting juice.

So it makes me think..is it the wires or somethings else causing this?

[pdlrofdrms]

When I googled erratic misfiring cylinder this is what I found:

If fuel pressure is within specifications, check the intake vacuum to see if there is an air leak that's upsetting the overall air/fuel mixture. A couple of overlooked causes here may be a leaky EGR valve or a leaky power brake booster.

mmm...Off to find the culprit. I will have some time tomorrow to work on her so any next step advice would be rad.
Thanks

[airkooledchris]

I took out my timing lite and now 1 and 3 are missing and not consistently getting juice.

Does swapping in the old wires change the behavior with 1&3 the same way it did for #2?


To others reading the updates on this case:

We connected the timing light to each of the plug wires and just watched the light, and #2 was randomly skipping a spark here and there. Swapping out the "new" plug wire with an old one stopped the behavior right away.

If it's doing it on 1 and 3 now also, while I would try swapping the plug wires with the old ones just as a test, id also think about double checking the dwell (points) and the cap and rotor to see how they look.

If nothing is found there, maybe try also swapping the old/new wire from the coil to the distributor.

[Amskeptic]

I took out my timing lite and now 1 and 3 are missing and not consistently getting juice.

Does swapping in the old wires change the behavior with 1&3 the same way it did for #2?


To others reading the updates on this case:

We connected the timing light to each of the plug wires and just watched the light, and #2 was randomly skipping a spark here and there. Swapping out the "new" plug wire with an old one stopped the behavior right away.

If it's doing it on 1 and 3 now also, while I would try swapping the plug wires with the old ones just as a test, id also think about double checking the dwell (points) and the cap and rotor to see how they look.

If nothing is found there, maybe try also swapping the old/new wire from the coil to the distributor.

Check that the booster hose from the engine is going to the connection on the booster can itself!
The brake rod boot hose goes to the left drivers side B pillar!

Get thee a new Bosch spark plug wire set (the good ones).
ColinMiami-bound

[pdlrofdrms]

[
Check that the booster hose from the engine is going to the connection on the booster can itself!
The brake rod boot hose goes to the left drivers side B pillar!

Get thee a new Bosch spark plug wire set (the good ones).
ColinMiami-bound

I will get another set of wires and recheck the hose. My old wires were practically brand new and are the good bosch ones. Mmmm...I am thinking its the booster hose. I am going to keep my mind open however. AND I did back in the day do a OHM test on the old wires to see if they were viable. Two were not so I got a new set. I will test my current ones. I totally forgot about doing that.

[airkooledchris]

Get thee a new Bosch spark plug wire set (the good ones).
ColinMiami-bound

Where? Aren't all of the Bosch ones the Mexico made ones now with the Mag core?

Mine have seen better days, but they are still copper core which is supposedly much better.

[pdlrofdrms]

Well Airkooledchris now I have to more homework. LOL What spark plug wires are the "best" I did find a few great articles.
And that you can make your own!!

[airkooledchris]

Well Airkooledchris now I have to more homework. LOL What spark plug wires are the "best" I did find a few great articles.
And that you can make your own!!

I have to say, I was looking at that to and I love the idea of making my own cables. More homework needed for me on that front also... ill report back if I figure anything out first, but that's unlikely. :P (I'll copy you when you work it out!)

[Amskeptic]

Well Airkooledchris now I have to more homework. LOL What spark plug wires are the "best" I did find a few great articles.
And that you can make your own!!

I have to say, I was looking at that to and I love the idea of making my own cables. More homework needed for me on that front also... ill report back if I figure anything out first, but that's unlikely. :P (I'll copy you when you work it out!)

Get the Bosch 7mm silicone blah blah blah grey with the *correct boots and correct phenolic connectors (two short and two long). Treat them with respect and use a little lube when you press them into the plastic clips and they will last for at least as long as the engine. People wreck these things by pulling on the wires instead of the connectors or ripping the insulation when they tear them out of the plastic clips, or letting oil leaks drench them.
You can custom size each wire with this set, the bare ends screw into the connectors.
Do NOT get the cheapy black wire sets that shock the hell out of you when you try to do a cylinder drop test. Been there . . .
Colin

[pdlrofdrms]

Get the Bosch 7mm silicone blah blah blah grey with the *correct boots and correct phenolic connectors (two short and two long). Treat them with respect and use a little lube when you press them into the plastic clips and they will last for at least as long as the engine. People wreck these things by pulling on the wires instead of the connectors or ripping the insulation when they tear them out of the plastic clips, or letting oil leaks drench them.
You can custom size each wire with this set, the bare ends screw into the connectors.
Do NOT get the cheapy black wire sets that shock the hell out of you when you try to do a cylinder drop test. Been there . . .
Colin

My set is that set. And I do lube them. I am going to test them. I don't think its the wires. Too coincidental. All the wires have the correct phenolic connectors ( new word I need to look up) LOL
No oil leaks that I know of yet. Have all the boots. Seriously the set is about a year old I think. Not sure exactly but pretty new.

So thats why one of my questions was how often does one replace ignition wires?

I will test them soon. I have a ton of work to catch up on so I will report back with new findings thanks for the help and direction. Gonna take a solid look at the Brake Booster Hose from Booster to motor.

Still can believe my hose was severed and melted

[pdlrofdrms]

Okay so there is a vacuum leak in the brake system.

I found this out by removing the check valve plugging the line to the engine with bolt and clamping it down.
Engine ran great.

All cylinders firing even and participating. No more lumpy idle.

So now I have crawled under the car with a big ol flash light. I checked the connections and looked for tears, holes, etc.. none that I can see.

I called my VW friend in SD. He said its not super common but sometimes the metal tubes can get holes in them and to run my hands along all the metal tubes and check for any rust and holes.

Sigh...
I did get a new brake booster and Master cylinder I was hoping to store it away until I actually needed it.
Maybe I actually need them.

I do not see any oil leaks at all around the seals and or connections.

So I feel a little stuck.

Back out to re examine the hoses.