Builds 1970 FatherSonJ40 project

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Ok good news, after sitting for about an hour, I was able to start it up and move it into my shop no problem. It’s definitely the brakes. It appears I’m building pressure that’s not releasing as I drive. Now to figure out why….

Probably burned about half the life off my clutch on the initial drive….
 
Rubber brake lines, when they go bad on the inside can end up acting like a check valve - you put on the brakes and they stay on for a long time. Just moving in and out of the shop no be deal but a long trip results in brake lock. Bad master/slave might do it too.
 
I’m hoping it didn’t bend the rod or something. I ran it about 300 yards with zero fluid in the power steering system to get it in my shop after the first pump failed. That could have been bad.

I also really jammed on the brake pedal last week when bleeding the new power steering pump on, so could have bent the rod then. My one drive last week was only about a mile tops so maybe not a good enough test.

Also could have blown up a rubber brake hose when needing the system this time. More investigation to be done.
 
If it's just the 1 caliper it could be the rubber hose at the knuckle as Charlie mentioned. If the other brakes are dragging too, it could be the rod between the master and booster. If the rod is adjusted too long, it will put pressure on the masters piston and will evetually build pressure in the system. If the frt disc brakes were adapted to a drum brake system you need to remove the frt residual valve inside the master cylinder. The residual valve keeps pressure in the line for the drum brakes.
 
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Fiddled a little today. I think it’s two issues- #1 is that the power steering reservoir was far too full. I siphoned some out to what looks right (the dipstick is tough to see clear fluid on!); #2 with the pushrod extension in the master, the pushrod coming from the booster appears to be 1/16th too long. I put it all back together with some 1/16th washers spacing out the master from the booster, started it up, brake pedal pushed in super easy, full travel, very slow rebound. Miffed and frustrated I went inside, called it a day and jumped it the shower. Wouldn’t you know it, went back to the shop and the pushrod extension is sitting there on my work bench. Doh. Will try again tomorrow hopefully.

On a side note, she’s really running rough, I think the 3 year old gas in the tank is really started to rear its ugly head. On we go.
 
Had some time to tinker today. Think I’ve fixed the brake issue. I adjusted the brake pedal, both on the pedal itself and the brake light stopper. Probably picked up 1/2in of pedal travel and the rod is fully extending out of the booster now. Whoops.

Also drained most of the gas and filled with 6 gallons of new, plus a new fuel filter. Didn’t go for a drive but let it run till hot in the driveway. Brakes don’t lock up.

Also man it is running rough. Definitely have a good miss (which is new). Pulled the #1 plug and dannnng its black. Carbon, not oily. It’s an NGK BPR5EY. Also has M98F on it. Is this an approved plug? Anyone have an approved gap for running Holley sniper EFI? Hoping to do a compression test and replace plugs tomorrow.

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Got new plugs in and gapped the same .05 that the old plugs were, already runs a ton better, think at this point I just need to run it really hard and blow it out.

Also did a cold compression test and I’m honestly shocked at the numbers - 130, 125, 130, 130, 123, 123. This is at 6,200ft of elevation too! Put my bore scope in it, the parts of the cylinder walls I could see looked great, piston tops looked wet and carboned up pretty good, definitely looking rich. Might have to lookup what system I need on the laptop to take a look at the tuning.
 
Just got back from a drive, definitely runs a ton better. Very happy with how it’s progressing. Now to just rebuild the doors and windows so the rattles aren’t deafening…

And get something on the floor to cut down on some of the awful loud drivetrain noise. The gear box and transfer whine is crazy!
 
Kmehr said:
Just got back from a drive, definitely runs a ton better. Very happy with how it’s progressing. Now to just rebuild the doors and windows so the rattles aren’t deafening…

And get something on the floor to cut down on some of the awful loud drivetrain noise. The gear box and transfer whine is crazy!
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It all part of the charm. Put some big muds on it and you won’t even notice the rest of the shakes, rattles and gear whine.
 
archie73 said:
It all part of the charm. Put some big muds on it and you won’t even notice the rest of the shakes, rattles and gear whine.
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Haha, I’m thinking just taking the top off completely will cure a bunch of that too…
 
Kmehr said:
Haha, I’m thinking just taking the top off completely will cure a bunch of that too…
Click to expand...
This has been my answer for the last eight years. Works just fine…
 
It occurred to me today that I basically lack just a bell housing to swap in the h55f and splitcase in my garage… I wonder if a fella did such a think behind his apparently solid compression 1.5F and later down the road swapped to a 12ht diesel if the transmission would end up in the same place?
 
Put a wrench on the balancer bolt of my 12ht yesterday to see how easy it spins over. Turns nicely about 350* in both directions, then there’s something stopping it. It feels solid, not like I’m trying to overcome compression, so I don’t want to force it. Uh oh. I’ve got a lot of other projects ahead of an engine swap, but sounds like I’m due a rebuild to some degree. The guy I bought it from in Canada did a compression test before i bought it, so maybe he put something back together wrong? The numbers were pretty close to spec but I can’t find the sheet he sent me now…
 
Not forcing things is a good plan. Maybe it locked by too much fuel/oil in a jug. A bore scope down the injector holes could be plan.
 
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