These are fittings sold by Coleman racing to adapt the hydroboost to normal russel or earl fittings. They solve all the problems of making lines for the hydroboost or the jeep box.

They are Allstar
GM Power steering Fittings
#ALL48210 6 male to 16 mm fitting with O ring $16.95 CDN
#ALL48212 6 male to 18 mm fitting with O ring $16.95 CDN

These fitting screw into the hydroboost or Jeep box and allow you to fit a standard #6 line.

Hope this helps anyone trying to do their own conversion. These are the fittings I used.

 

Thanks Norval this will be a big help!


Wade

 

Same I used too, I'm sure others will find this most useful stuff!

 

Link to website. Do these fit the GM racks also? I've already got the 6AN lines adapted to the old control valve, so a simple conversion adapter will save me a $100 large for new lines.

 

Great tip! I have a hydroboost unit that I struggled out of a GM conversion van (that was NOT a fun job in the summer heat!), and it's going in when I get around to the engine conversion. Now I just have to find the right power steering pump.

 

Another tip. Punch the 4 studs that come with the unit out of the plate on the hydroboost and put them in the firewall from the inside facing out. They press in like wheel studs in the existing holes in the forewall. Use a large nut and the proper nut to pull them into the firewall.
From now on removing/installing the unit is done from the outside and only takes a few minutes. I took mine off last night.

All power steering pumps will work with hydroboost.

 

Here are the GM power steering hose end connections as I remember them for GM vehicles:

C2/C3 Corvette Specific Hoses with Control Valve on the Linkage
1963 through 1979
Pump to Control Valve - High Pressure Hose
Pump End - 3/8 inch dia tubing with a 5/8-18 UNF male nut, 45 degree flare to mate to the female port in the pump discharge fitting.
Control Valve End - 1/4 inch dia tubing with a 7/16-24 NS male nut, 45 degree flare to mate to the female port in the control valve.

Control Valve to Power Cylinder Hoses (2)
1/4 inch dia tubing with 7/16-24 NS male nuts, 45 degree flare on both ends of the two hoses.

Control Valve to Reservoir - Low Pressure Return Line Hose
Control Valve End - 3/8 inch dia tubing with a 5/8-18 UNF male nut, 45 degree flare to mate to the female port in the control valve.

C3 Corvette 1980 through 1982
Pump to Control Valve - High Pressure Hose
3/8 inch dia tubing with a 16x1.5 metric male nut, o-ring connection to mate to the female port in the pump discharge fitting.

All other connections remained the same as above. They did not change to metric.



All Other GM Gear and Pump Ports
1). Some Chevrolet model power steering pumps from 1963 through 1969 had a male discharge fitting on the power steering pump. The high pressure hose required a female nut and 45 degree flare. I don't remember the size of the thread.

2). All GM integral power steering gears before 1980 had female
11/16-18 NS 45 degree flare high pressure inlet ports. They had female 5/8-18 UNF 45 degree flare low pressure outlet ports.

3). All GM integral power steering gears and rack and pinion steering gears from 1980 to present had female M18x1.5 o-ring high pressure inlet ports. They had female M16x1.5 o-ring low pressure outlet ports.


Hoses for Hydroboost Brake Units produced before 1980 for GM
Power Steering Pump to Hydroboost Inlet - High Pressure Hose
Pump End – dependent on the pump discharge fitting.
Booster End - 3/8 dia tubing with a 11/16-18 UNS male nut, 45 degree flare to mate to the female port in the booster unit.

Hydroboost Outlet to Power Steering Gear or Control Valve - High Pressure Hose
Booster End - 3/8 inch dia tubing with a 5/8-18 UNF male nut, 45 degree flare to mate to the female port in the booster.
Gear or Control Valve End – dependent upon the high pressure inlet port configuration.

Hydroboost Outlet to Pump Reservoir - Low Pressure Hose
I believe that it was just a 3/8 dia spout to mate to the 3/8 ID return line hose.

Hydroboost Brake Units from 1980 to present for GM
Power Steering Pump to Hydroboost Inlet - High Pressure Hose
Pump End – dependent on the pump discharge fitting.
Booster End - 3/8 dia tubing with a M18x1.5 male nut, o-ring connection to mate to the female port in the booster unit.

Hydroboost Outlet to Power Steering Gear or Control Valve - High Pressure Hose
Booster End - 3/8 inch dia tubing with a M16x1.5 male nut, o-ring connection to mate to the female port in the booster.
Gear or Control Valve End – dependent upon the high pressure inlet port configuration.

Hydroboost Outlet to Pump Reservoir - Low Pressure Hose
I believe that it was 3/8 dia tubing with a spout to mate to the 3/8 ID return line hose.

 

When I installed Steeriods and a F-body serp belt set up I was going to have a new hose made but the shop did not have the metric o-ring ends that screw into the f-body pump so I had them install a reg fitting (-6an I believe) on the f-body hose to screw into the rack, worked like a charm and cost $13. .

 

these adaptors are the metric O ring ends that convert it to a normal 6 an fitting

 

Great post Norval. Do you have any pictures of the hydroboost and how/where you installed it? Are the brakes still easy to control without locking up the wheels with this mod? Thanks

 

I have had the hydroboost on one of my vettes for some time. This is the way to go. I have no fluctuations in pedal feel like I used to due to the vacuum fluctuations. In fact, I think that the brakes are more precise and controllable eliminating any tendency to lock up.

 

Norval has some good info here.

I too pressed the studs in from the inside and for lines I used gates 4800 psi dual wire hydraulic lines that I made at my buddys Parts Plus store. I used some junk PVC hose to get the indexing of the 90 deg. ends with the curve in the hose.

 

So the hydroboost goes between the firewall and the master cylinder then ? Will a non-power brake master cylinder work with the hydroboost? I don't have the vacuum can, my MC is mounted directly to the firewall.

 

Yes I went from manual to hydroboost. The hydroboost fits the hole already there in the firewall, well the 4 studs line up but I did have to enlarge the center hole slightly.
The stock manual master cylinder while it does bolt up the center hole is too deep so the pushrod is too short.
To solve this I just turned another piston for the stock master with a shallow hole.
I would do this for you Smoked Tires. I would just pop my rear piston out , whip up another and send you one that you could substitute and it would be billet aluminum not cast, A custom piece.
I can also add about .010 to the O ring groves to make the seals a little tighter,'
If you go that route let me know and I will make the part

 

Is the power brake MC a direct bolt-on to the Hydroboost unit? Do any modifications have to be made to the pedal side? I think I have a thread bookmarked somewhere showing how to hook up the lines.

 

There are two types of vette master cylinders on the C3, one with a shallow and one with a deep hole in the center of the piston. The shallow one is from a newer model C3. The hydraboost goes in between the master cylinder and the flywheel and replaces the vacuum booster assembly. Depending on where you get the hydraboost, the bolt holes on the firewall side will or will not directly bolt up. The master cylinder side, it is a direct bolt in. On the one that I got from an 85 military CUCV diesel pickup, I had to drill the lower two holes. The center and the upper two holes matched. Also, I had to extend my brake lines. But everything else is a bolt in.