Amazon Wagon #2, Electric Bluegaloo

[propav8r]

With the return port blocked the brakes will work normally until the fluid heats up and expands. It can't get into the reservoir so it pushes the pistons out of the calipers and applies the brakes. You probably introduced some air into the system when you opened the bleeder which explains why it only dragged slightly on your last drive. Either that or you didn't get them hot enough to fully lock up.

Some drum brake master cylinders have a check valve to prevent fluid from draining back into the reservoir that will cause similar symptoms. Generally they are low mounted masters. Wilwood sells residual pressure valves for cars with masters mounted under the floorboards since modern master cylinders don't have the built in check valve. PV's are that way so the check valve must be removed when converting to front disc or they will lock the front brakes when the fluid heats up. I doubt that's your problem though.

That’s a very good point. Maybe that is it.

 

[hiperfauto]

It's easy enough to check. Just pull the boot off the back of the master and make sure the piston is all the way back against the circlip or whatever retains it. If not, the pushrod is too long.

 

[JohnMc]

The port gets covered when the piston is *barely* in.

Might tie in with difficulties bleeding the brakes as well, the system will have a harder time pulling fluid in. It can work, but only by pulling fluid past the piston seals since they don't seal well against suction.

 

[propav8r]

Yeah, I don't think it's necessarily the ball, but the combination of the ball and the slotted washer. This master didn't' originally have a captive pushrod, I had to sandwich the slotted washer under the snap ring that retains the piston. I bet that's doing it. As much as I've been in denial about it not, now that I sit down and think about it and listen to y'all it makes sense.

I think I'm going to try to modify this master to make it work. I'll put a stud in the piston that sticks out, thread a clevis onto that, and then use the clevis at the pedal as well. That way, I don't push the piston in at all but I still have a way to retain the pushrod.

 

[hiperfauto]

When Volvo went to dual circuit masters in '68 they also didn't have a pushrod that was attached to the master cylinder. Instead there was a brake light switch and bracket under the dash that limited the pedal travel so the pushrod didn't fall out of the back of the master. The original pressure switch port in the splitter was plugged and the wires rerouted to inside the car. Some drilling is required to mount the bracket.

Ron Kwas is reproducing the bracket. We probably have an original in storage but we're out of town for a couple of weeks.

SW-EM Kits

sw-em.com

 

[JohnMc]

You might try taking a washer's thickness off the end of the piston? Or at least look at it and see if that is feasible. Might be easier than rethinking the linkage.

 

[propav8r]

You might try taking a washer's thickness off the end of the piston? Or at least look at it and see if that is feasible. Might be easier than rethinking the linkage.

Yeah, that's another option, and you're right, probably easier.

 

[propav8r]

Also, fwiw the Mazda does have a residual pressure valve in the fitting for the rear circuit, but the rear brakes seem to work fine with that and the stock proportioning valve so I'll probably just leave that alone.

 

[JohnMc]

And you'd want that with the rear drum brakes. You'd just need to remove it if you had rear discs.

 

[propav8r]

So my replacement free master cylinder showed up yesterday (thanks daddy Bezos) so I can mess with that on the bench and yep, the return port to the reservoir is blocked when the piston is depressed even a slight amount. I have a plan though.

 

[propav8r]

Well this thing is rapidly approaching the "done enough to drive to a Turbobricks meet" level of completion.

Got the brakes sorted out, @hiperfauto and like 7 other people were correct. Putting the captive washer and pushrod under the snap ring that retains the piston was pushing it far enough down the bore to block the return path of the fluid, so I just did this:

That's a clutch master pushrod with a different profile ball, and there's just a few thou of free play, so I'm not preloading the piston at all. Seems to work well. In the end I'll admit that it would've been easier to just use the later dual circuit master, but dammit, this is Turbobricks.

I did have some headaches adjusting the rear brakes because when I packed the adjuster all the way off to pull the drums, apparently something galled or stuck, and it was super hard to get the adjuster screw moving again. I took the whole adjuster assembly off the backing plate and pulled out the adjuster sliders and still couldn't get the screw moving. Some persuasion with a 10mm 1/4" drive socket flipped over backwards and a 10mm hex key on a 1/2" drive socket popped it free.

Once I had the rear brakes adjusted, the pedal feels nice and consistent, and the brakes work well. Luckily it seems that I don't have any leaking calipers after the rebuild, that was my main concern.

After that, I gave the thing a Comet wash and that took care of a lot of the rust staining and generally evened out the paint. Got the front and back bumpers on too, though I am short one bracket for the rear. I'll probably just make that though, it seems like a simple piece.

The last immediate mechanical problem was the fact that no matter what I did, when I ran it off the fuel tank the car would stop running after a few minutes, sometimes 2 or 3, sometimes 10.

I noticed that the stream of fuel being pumped out was a trickle at best. I was sort of convinced that the fuel filters were getting pretty immediately plugged and consigned myself to pulling the tank. When I pulled up the spare tire rubber mat, everything looked pristine. Even the sender was still looking like brand new.

I borescoped the tank and it didn't really look bad, so I just hooked a piece of fuel line to the metal stub under the hood and tried to blow backwards into the tank and just couldn't.

Then, I hooked up a blow gun to the compressor and fed it 40-50psi of shop air. After a second, I heard a *pop* and then bubbling from the tank. I guess the line was just plugged with something, who knows what. After that, I hooked the pump back up, and the pump started spitting out a more reasonable amount of fuel (that was much cleaner to boot)

That called for a celebratory beverage, so the family hopped in and we drove the half mile or so to the closest spot:

And then dropped it off at the glass shop for a new windshield:

I need to get the missing trim pieces on (I have the trim, just not the clips), have some sort of exhaust cobbled up, and then it's basically Kylemeet ready!

 

[propav8r]

And a video update:

 

[James M]

That called for a celebratory beverage, so the family hopped in and we drove the half mile or so to the closest spot:

You know you've made progress when it works well enough to convince unsuspecting family members to ride in it

Washer welded to the master is the perfect level of TB, definitely closing in on Kylemeet ready!

 

[propav8r]

So, update time:

New windshield is installed and looks okay. The seal must be different on the inside because the metal interior trim doesn't want to slot right back in. I may need some longer screws for that. Idk what the deal is.

I am still fighting fueling issues. I kinda assumed that the pump was sucking up trash which wound up killing it occasionally, but I don't think that's the case now. I finally just gave up and put an electric pump on to eliminate the variable of a 40 year old pump. That seems to work okay, but I drove it to work this morning and when I got there, the clear filter (post pump) was just about dry. This is the same symptom as what I was seeing with the mechanical pump. The car was running fine when I pulled in, but in the driveway the filter would fill up to about 75% or so. I'm going to drive it some more here in a bit and see if it dies again. This is just so weird. My next step may just be to run a fresh line from the tank all the way to the front of the car.

At least this time I was able to coast into a parts store.

What else...oh, the voltage regulator is on the fritz it seems. When I was looking for a terminal to hook the electric pump to, I realized the thing was charging at 15v at idle, up to about 18v at 4k rpm. That might explain why the headlights were so bright.

Through the sage advice of @JohnMc, I cleaned the contacts on the regulator and bent the little tabs on the regulator coil a bit. It now charges at 13.2-13.5v at higher RPMs and about 12.8v at idle. At some points in the lower rev range the cutout relay kinda clicks back and forth, and the voltage will briefly jump to 14.7-15v which makes the amp light blink sometimes, but the voltage seems to hold relatively steady.

I am going to fast track the alternator conversion, this generator is ancient and has a little bearing noise, and isn't getting any younger. Just wanna head that problem off at the pass.

 

[JohnMc]

Someone may have bent the tab up to try and make it charge at idle, and generators just aren't going to do that.

 

[propav8r]

Ordered the sw-em alternator kit.

I think my fuel pickup problem is the actual pipe in the tank. I’ve noticed that when I run the electric pump, I see a bunch of bubbles coming up into the filter like it’s sucking air from somewhere.

I’m willing to bet that the pickup pipe in the tank has a hole in it, which is creating an air break at basically any fuel level below 3/4.

I’m going use the fuel tank drain fitting as my new supply fitting, and run a new hard line all the way up.

I also think I’m gonna try a new mechanical pump after I do that. I really hate the way the electric pump looks and there’s not a great place to mount it in the back without drilling holes for a bracket or welding something to the body.

We’ll see.

 

[propav8r]

We're back! With never-before-seen levels of reliability!

So the pickup tube in the tank is fine it seems. There was just so much rust and crap in the tank that it was repeatedly clogging the pickup, both the tube and the drain fitting.

I finally bit the bullet Saturday and just pulled the tank out and cleaned it the best I could with a pressure washer. I could've certainly tried electrolysis (and still might in the future) but the time crunch for Kylemeet precluded that. I dumped probably 2 pounds of rust out of this thing.

At one point when I was trying to avoid pulling the tank for some reason, I ran across this fitting for Massey Ferguson tractors:

I figured I could put this in the 1/8 NPT fitting for the drain and it would prevent the chunks of rust from clogging up the drain line. Then I woke up the next morning and realized how stupid that was and that it would be just kicking the can down the road, so I pulled the tank, pressure washed it, and reinstalled it. So far so good.

It's much better now, I'm working on a video that'll show the results.

What else...oh, alternator conversion is done. Rear suspension bushings are done. Front suspension bushings are done. Shocks are done. Ball joints are done. Steering linkage is done. All the lights work except for the reverse lights, and I found out that my no-taillight situation was because someone had swapped a couple of wires on the headlight switch and hooked the instrument panel wire to the terminal for the taillights and vice versa.

I also cleaned up the switch and addressed some issues internally on that, so all my lights (except for reverse lights) work.

I put some aluminum hvac tape on the brake light reflector to try and make it actually reflect some light. Seems to work okay. I also ordered some mega bright LED 1157 bulbs to further improve brake light visibility and cobbled up a pedal position switch so the brake lights actually turn on without stomping on the pedal now.

Bracket looks a little cockeyed but it works juuust fine.

Loaded up the family for a 60-mile shakedown cruise on local roads and it did great. We went up Windingstair gap, about an 1800' climb in 6 miles. Got to the top, parked the car for pictures, and when I went to restart it it idled super high and then died, pretty indicative of vapor lock. We coasted down the long hill and let things cool off and it fired right up and went back to happily pumping fuel.

And the required stop for Cook Out milkshakes on the way home

Overall it did great. Definitely has some gear whine/clunking from the diff but I think that's just the result of it being almost 60 years old. I do have a gasket for the diff cover and I'll probably drain and refill that sometime this week but that's about the last piece of maintenance I need to do to feel like I've done everything I can for the trip.

 

[propav8r]

Aaaaaand it died again on lunch break. No fuel to the engine.

Time to borescope the tank and take a look at the condition of the pickup tube.

 

[Quin]

classic case. you jinxed it by having confidence in it.

 

[propav8r]

classic case. you jinxed it by having confidence in it.

I pulled the boat gas tank out of the back this morning, clearly that's a magical talisman.