Re-Rebuilding the 440-493 in a 1970 Charger

[Kern Dog]

Nobody I know has a way to test power steering pump pressure.
The power steering pump hasn't been a problem since I replaced it in 2006. Suddenly, I wear out 2 pumps in a week?

 

[CoronetDarter]

You can buy VR1 in a non synthetic as well. That's what I run anyway....

But in CA you have to ship it from Summit. Retailers here can't sell it. I believe CA regulators found that rats that drank large quantities of VR1 developed cancer.

 

[NoCar2023]

If you decide to keep the h-boost setup, I have a couple of ideas.

 

[4406bbl]

Nobody I know has a way to test power steering pump pressure.
The power steering pump hasn't been a problem since I replaced it in 2006. Suddenly, I wear out 2 pumps in a week?

To test it you build a gauge set with a shutoff valve on the outlet. With the engine at 1500rpm you shut the outlet valve and read the pressure. On a dodge with that hydroboost unit you need 1450-1550 psi, and 3.1 gallons of flow per minute with no restriction on the line, another hard test because you need 5 glons of fluid and 2 guys. That said with only one washer on the relief valve I doubt the pump is the problem. You can put the relief valve in backwards and have really low pressure, it happens when you get tired, don't ask how I know that, so if you know you did not do that, I say the hydroboost is bad. If you get it to work I think you will like it, my 2000 diesel will put you thru the windshield with very little pedal pressure, and maybe an inch of travel even
with an 1.25" master cylinder.

 

[68 Sport Satellite]

KD, you've also got the Borgeson steering box as part of this equation. Could that be contributing to too much line pressure?

 

[Kern Dog]

I thought the Borgeson required more pressure than the stock Mopar gear.
From what I recall, Rick Ehrenberg stated that the V8 Saginaw pumps put out over 1100-1200 psi but the slant six models came with less than 900.
Regardless...I drove the car for only a week with the Borgeson box but it worked great. No hissing, no growling, great assist at all engine speeds.
I suspect that the fluid is bypassing the flow control valve that powers the ram in the HB. At this point, I am burned out with it.
You all may have experienced the same thing where you work like hell to get something working but it fights you at every turn. Sometimes you might get more satisfaction by abandoning the idea and going with something else.

 

[CoronetDarter]

This is a fascinating thread on many levels, at the same time I'm sorry the braking system has been such a fight. This hobby of ours can be real frustrating at times.
We're all learning a lot from your posts and thanks for sharing the lows along with the highs. I know you'll figure it out.

 

[6872n73]

Something to thinks about.

Pulling Out All the Stops with Hydroboost Brakes

How hard is a Hydroboost brake system conversion on a Chevy 350-powered 1940 Ford fat-fender Coupe with Low Idle Vacuum that won’t stop, and are there other solutions?

www.google.com

 

[Kern Dog]

Disassembly has begun.

This is the easy part. Master cylinder, hard lines and hydraulic lines are easily reached and removed.

The 4 bolts that retain the HB are no different from the same that retain a vacuum booster or a manual master cylinder. The nuts are on the interior side way up below the dash. If you are thin, young or flexible , this isn’t bad. Some people will remove the seat. I pulled the steering wheel since it is an aftermarket one held on with 5 Allen screws.

They sure pack a lot of stuff in a small space, especially with a manual transmission. The brake pedal pushrod has to come out. I used a bent wrench to access the hardware.

The clutch and the brake pedal are coming out. To do that, the fresh air box has to come out to get the room to slide the hinge pin out.

 

[Kern Dog]

As it turns out, the clutch pedal can stay. I slid the hinge pin back just enough to get the brake pedal out.

The bare metal pedal is what I had in this car before I did the 5 speed swap last year. Note the welded washers:
Here is why.

Center to center from the hinge to the pushrod hole on the manual pedal is 1 3/4”.

Center to center on the automatic pedal is….

Yes, 1 1/2”. A quarter inch doesn’t seem like much but it does improve the pedal ratio. I noticed a bit of a loss of brake force when I switched these pedals during the 5 speed installation and that was with the power booster that had reduction linkage in it:

Now I had a choice to make. Do I drill the manual pedal or cut the automatic pedal?

 

[Kern Dog]

Boom.

A few moments to cut the pad and smooth the edges….

I cleaned it up and hung it from wire to prime and paint….

By tomorrow it should be dry enough to install.
I decided to modify this pedal because if the manual master cylinder setup isn’t adequate, I want the manual pedal intact. If I try a vacuum booster, I’d prefer to start from a “stock” baseline.

 

[Kern Dog]

The Hydroboost is out....

This fits in a USPS flat rate box. I'll contact Dr Diff through email to thank him for the offer.

I'll package it better and make sure it is well padded for transport.

The master cylinder needs to be bench bled.

The 4 to 2 adapter came with those same button head Allen head bolts. They look slick but make it hard to fasten when you don't have another person on the inside of the car tightening the nuts.

I'm going to use these black 6 point hex bolts with the shouldered edge. I need two more.

They look nice and allow me a flat surface to attach vice grips to keep the bolt from spinning.

I still have plenty of the DOT 5 brake fluid.

I hope to have it back together tomorrow. Mary is away on business so I'll have to try bleeding the system alone. I've never had much luck with that but I'm going to try anyway.

 

[Kern Dog]

Goal set, goal met....

First up, I bench bled the new master cylinder and capped the ports.

The 4 bolt to 2 bolt adapter sits against the firewall stiffening plate. I figured there should be some sort of foam seal between them. I took some of my stock...

Traced and cut it to size...

Then, the hard part.....bolting it in.

This isn't difficult with a second person on the inside of the car. To do it alone, I just put vice grips on the bolt heads on the engine side and tightened the nuts from inside. Again, removing the steering wheel or seat helps a LOT.

The master cylinder and hard lines are in. Man.....this looks so much cleaner.

I really hope that this manual setup works well. If not, I'll take my lumps and install a booster.

 

[khryslerkid]

I've never had much luck with that but I'm going to try anyway.

Here's my helper. Stinky cheese container, Pringle can with a section of chain inside for weight, section of hose.

Make sure the hose is submerged in fluid. Right rear, left rear, right front, left front. One time for each wheel and I had a solid pedal.

Forgot to mention I'm not doing gravity bleed here. I push the pedal to the floor, slowly, two or three times. Then go under and tighten the bleeder. I just crack the bleeder, not open too far so it won't suck air in around the threads. If it's real quite in the shop you might hear air bubbling in the jar. Check master cylinder fluid level after each wheel.

 

[Kern Dog]

Thank you. I have had mixed luck with the self bleed efforts that I've done but I will try again.
Here is an observation that I stumbled upon:
I had the wife in the car doing the pedal pumping while I was out cracking bleeder screws and getting very little fluid to the right rear after several attempts. She asked why I started at the rear. I told her that it is customary to do the furthest wheel away from the master cylinder first. She thought it made more sense to bleed the front first since the front calipers took a lot more fluid than the rear.
What the heck...I gave it a try.
The fronts bled out fast, then I went to the right rear and got pressure and fluid right away.
Two possible explanations for this from what I can see:
1) Her idea worked despite going against the traditional method.
2) The fluid was probably already ready to flow at the rear wheel and I walked away to do the front.
Regardless, I am always willing to consider alternate ideas when traditional methods are not working.

Lately I've been reading through Andy Finkbeiner's book, "B Body upgrades". One interesting topic that I read was in regards to brake bias front to rear.
Andy stated that determining proper bias in a front disc-rear drum setup is best left to factory setups. With a 4 wheel disc arrangement, you want a 2 to 1 bias. He explained that you want twice the front caliper surface area compared to the rear.
This explains the science behind this front and rear brake kit that he offers and that I bought. The front rotors are 13" and the calipers have two 1.59" pistons. The rear rotors are 11.7" and have a single 1.5" piston. These are FORD based brakes and the 2 to 1 bias is pretty close on this setup.
Doing the math, the twin piston surface area is 3.69. The surface area of the rear caliper piston is 1.76". This isn't exactly 2 to 1 but it is pretty close.
In 2012 when I tried several manual master cylinders, I had a 2.75" single piston front caliper. This had a 5.93" surface area. This resulted in a 3.37 to 1 brake bias. This might explain why the braking was so terrible. In addition, I had a disc/drum proportioning valve in there to make it worse.

 

[CoronetDarter]

If you are thin, young or flexible , this isn’t bad. Some people will remove the seat.

View attachment 1370546

View attachment 1370548

Yep. At my age, if a fuse needs replacing I remove the seat first.

 

[CoronetDarter]

Whatever you do, don't attribute your success to her suggestion. You'll never live it down.

 

[Kern Dog]

Oh, I am as honest with her as a person can be. I give her credit when she earns it. I'm not worried about her becoming overconfident. She is a well grounded person.

 

[CoronetDarter]

Yeah. There have been times that Maria has suggested another direction based upon pure ignorance and it was the correct call. A lot of times a fresh set of eyes is what it takes.

 

[1 Wild R/T]

Greg, The longest line method has it's reasons and that applies more directly in a single circuit system but with a split system like Mopars have starting in 67 there is a spool valve that will shift off center if there is a pressure imbalance preventing fluid flow to the side of the system that it perceives as having low pressure...

So you treat it as two systems, bleed the longest line on the side of the system with flow first and try to balance the pressure so the spool self centers allowing you to bleed the other side of the system...