Yes and Yes. I installed stainless hoses to the calipers, and saved the originals. Have tried 3 sets of different pads, HPS,,, organic,, semi metallic and the ones that came on the car. All options,,,, manual,, power brakes RPO J50,, and HD brakes RPO J56 all have the same block, switch, valve.

Are you getting really good flow out of your bleeders?
Have you replaced the hoses to the calipers?

 

Did the new front hoses come with copper washers?
Only the front calipers get the crush washers.

 

I gravity bleed my brakes. I have I have it down to an art. It is a zen experience with the timing equal to one beer per wheel. 🙏🏻🍺

 

I think so, what ever they came with. I removed the front pads, sanded them, cleaned them, cleaned the rotors, bled them again. The one thing about using a pressure bleeder, you don't really address air trapped in the MC. If you raise the rear of the car so the reservoir is higher at the rear, you can see bubbles coming out in each end, by pumping the brakes.

 

I thought you said you got all air out of MC when you bench bled it,,, (per post #16)
Curious, how high must the rear wheels be off the ground to make the rear of reservoir higher than front? 🤔

 

I didn't say I had air in the MC. All I am saying is,,,,, IF there is air in the MC, either gravity or pressure bleeding probably wont push air in the MC out. Rear wheels, maybe 6 to 8 inches is enough to tilt the MC forward, not that hard.

 

So, with all the awesome information you have received in this post, have you determined where the air comeing out of the rear outer bleeder valves originates ?

 

The copper crush washers must be installed between the front calipers line port and the rubber hose. Its a "one time" deal. You crush it when torqueing down the hose fitting which is usually done in a bench vise first, then the whole unit is installed on the car. The special washer can not or should not be used again. Without the crush washer, you will likely develop a fluid leak. Without it, you may or may not develop an air leak.

I never jack-up, tilt, slope, a car to bleed the brake system. You can bet the factory, nor any repair shop did back then or does now.

The Motive tank does address the bubbles in the MC. In fact, some people skip the whole "bench bleed" procedure because they have 100% confidence in the Motive tank. Myself, I use both methods.
The whole idea of the Motive tank is to force out bubbles in the MC and so on. If you use your Motive as nothing but an air tank because you don't have an air compressor, I believe you are asking for more issues. If the Motive tank has DOT3 in it, its design is to chase bubbles out the bleeders. Just that simple.

 

True, you have the bleed the MC. I find it easier on the car, using the pedal.



This is my C2, but the concept is the same. Keep these lines submerged in brake fluid and pump the pedal until no more bubbles appear. Being on the car, it is almost impossible to overextend the piston.

Gravity bleeding is just crack the bleeders and watch the bubbles.



Crack the bleeder, drink a beer and let gravity do the work.


Contrary to popular belief, it doesn’t matter where you start.

What does matter on dual bleeder calipers is to bleed the inner one first, then the outer.

For these Wilwood calipers, the rears needed to be hung vertically and given a few taps with the handle of a screw driver to get the last few bubbles out.

 

I'm trying to figure out how to use my new Motive bleeder with my air compressor.

 

I would not do that.

 

Did you really just post this?

Ok, I now realize there is no fix for your issues,,, sorry I couldn't help more,,, teddy ,,

 

Read HeadsU.P. post. I am responding to his post.

HeadsUP,,,,, " If you use your Motive as nothing but an air tank because you don't have an air compressor, I believe you are asking for more issues".

 

There are a couple NOS and one used #3904303 on eBay to compare to - https://www.ebay.com/3904303. Paragon Corvette's replacement looks like the ebay ones to me. I'll snap a pic of my '67's 3904303 to attach here too since both years use the same part. You are correct that there are only 4 ports w/one electrical. The '67 and '68 used this block mounted right next to the M/C and a secondary splitter for the front lines down on the chassis rather than the '69 onward where they moved this block down to the chassis and added a port for both front lines thus eliminating the second splitter block.

PS - I also read the HeadsU.P. comment about using a compressor and was hoping for clarification on that.

 

True. Thank you!

 

My ante poker chips are in the center of the table. My dealt hand is laying face-up on edge of the table.
I am out of this game.

Good Luck

 

Exactly!!!

 

I'll bite, then I'm out.

There are two ways to use the Motive bleeder. You can add brake fluid, and force it through your MC. This is how @HeadsU.P. does it, and how the directions say to do it. This method may cause you to spill brake fluid in your engine compartment, but it will also force air bubbles out of your MC.

The other way, and the way I do it (image in Post 2) is to use the Motive pressure bleeder as a source of compressed air. I fill the MC with brake fluid, clamp the adaptor cap on (I use quick clamp now, a screw clamp is shown), and use the pressure from the Motive reservoir to push through half of the brake fluid. Then I uncap it, add more, and repeat. This way avoids the possibility of having pressurized brake fluid pour out of the Motive reservoir, but if you mess up and let the MC run dry, you've now added air to the MC, and may need to bench bleed it again.

I was fortunate enough to have a master mechanic teach me the first method years ago, with system similar to the Motive, but no doubt costing 10 times as much. Once you see it, either on Youtube or in person, it is easier to understand. I don't bother with them, but if there is a Corvette Club (or even just a classic car club, or 4x4 club, or whatever) near you that works on their own cars, it may be worth joining to get some hands-on experience. Offer to host a meeting where you fix your brakes.

 

Hopefully, just one more reply!
About how much pressure are you pumping up the Motive? Does it matter?

Thanks for the breakdown of the two methods. I now understand how some folks are using garden sprayers -- it's just a pressure vessel to drive the fluid from the M/C.

 

I wasn't using much, 5 to 10 psi, using method 2 (air only). I didn't have an issue with the combination valve using this method, but there exists a tool that will hold it on center. I also used two bleeder bottles so I could do both sides of one rear caliper at the same time.