Hydraboost

Reply Subscribe

Thread Tools

Search this Thread

Mar 24, 2019 | 12:06 PM

#21

slyfox2062

Thread Starter

Instructor

Joined: Jul 2009

Posts: 155

Likes: 0

Quote:

Originally Posted by pauldana

Wrong rod

the small ~2”? Rod that is inserted in the master brake cylinder, this rod just falls out
nothing holds it in

yes the rod pulls out but mine is 4.5 inches long as deep hole in MC piston. Butting the two together does not apply pressure to the MC piston. I can appreciate the Pedal input may not be enough to shift the HB valve to engage the power section being limited by the brake hydraulics and little movement in the pads, I guess the other extreme means too much pedal movement before brakes apply which would occur if the rod was too short. I need to experiment again on the road as difficult to tell on the workshop floor. Cheers

Mar 24, 2019 | 12:07 PM

#22

'75

Le Mans Master

Joined: Dec 2007

Posts: 6,422

Likes: 591

From: McHenry Illinois

Usually there is a clevis with a jam nut on the pedal end of the rod.

Mar 24, 2019 | 04:00 PM

#23

chevymans 77

Melting Slicks

Joined: May 2002

Posts: 2,716

Likes: 121

From: Sulphur LA

St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25

visit the bottom of this page and take a look at the two side by side,

http://www.hydratechbraking.com/C3Corvette.html

You can see how far the rod should be sticking out of the HB units based on which one you have.

based on your photos you have the correct rod for the MC

Neal

Last edited by chevymans 77; Mar 24, 2019 at 04:02 PM.

Mar 26, 2019 | 12:34 AM

#24

caskiguy

Le Mans Master

Joined: Nov 2016

Posts: 9,215

Likes: 943

From: Lake Tahoe, CA

Quote:

Originally Posted by slyfox2062

Hi Guys, sorry I've been away a while. I have sorted out my rough idle and fuel mixture, the engine is pretty sweet now. I also redid my brakes new rotors, pads and calipers. Now I'm still suffering with lack of stopping power.

Will the rod length if incorrect between the HB and MC cause reduced braking power? I also notice that when braking the steering wheel kinda snatches a little, definitely feel something on the wheel when applying brakes. I don't think that is correct as the accumulator should apply brake pressure and not take it from the steering.

Is there a test to check the hydroboost operation?

Regards,

Greg

This may help. http://corvettec3.ca/hydro.htm

Mar 31, 2019 | 10:18 AM

#25

slyfox2062

Thread Starter

Instructor

Joined: Jul 2009

Posts: 155

Likes: 0

Thanks for the link.

I have now shortened the rod by 1/4 inch and road tested, still no appreciable difference in braking, I then created the gap between MC and HB to 1/4 inch and some improvement and some other observations. When engine off and pressed brake pedal several times then start the engine while holding brake down I was expecting the pedal to rise, this did not happen until I turned the wheel then felt pressure pushing the pedal up? Also when driving the brakes were more effective when the steering wheel is being turned? Could this be the hose arrangement I have at the T connector behind the PS pump? Could the system still be bleeding out? Even after closing the gap between HB and MC it felt improved but only when turning the wheel. Any other suggestions? I'm reluctant to cut the rod another 1/4 inch at this time. Regards Greg

Mar 31, 2019 | 10:31 AM

#26

caskiguy

Le Mans Master

Joined: Nov 2016

Posts: 9,215

Likes: 943

From: Lake Tahoe, CA

While I saved the provided link for future reference, I personally do not have the knowledge to answer your questions. You might consider contacting the following (provided in my link) to give you a good answer.

http://hydratechbraking.com/

Apr 1, 2019 | 10:05 PM

#27

slyfox2062

Thread Starter

Instructor

Joined: Jul 2009

Posts: 155

Likes: 0

Thanks for the replies. I’m now getting somewhere as found the fluid level gone low probably due to the HB valve now operating with the shorter rod. I keep reading how the system can take 500 miles to expel all air and system settle in so let’s see how it goes. Thanks for all the help. Regards Greg

Apr 1, 2019 | 10:18 PM

#28

pauldana

Race Director

Joined: May 2003

Posts: 10,956

Likes: 409

From: California

Quote:

Originally Posted by slyfox2062

Thanks for the link.

I have now shortened the rod by 1/4 inch and road tested, still no appreciable difference in braking, I then created the gap between MC and HB to 1/4 inch and some improvement and some other observations. When engine off and pressed brake pedal several times then start the engine while holding brake down I was expecting the pedal to rise, this did not happen until I turned the wheel then felt pressure pushing the pedal up? Also when driving the brakes were more effective when the steering wheel is being turned? Could this be the hose arrangement I have at the T connector behind the PS pump? Could the system still be bleeding out? Even after closing the gap between HB and MC it felt improved but only when turning the wheel. Any other suggestions? I'm reluctant to cut the rod another 1/4 inch at this time. Regards Greg

Bolded is what i was talking about
yes 500 miles city mostly stop and go and turns.

They make a PS pump can with 2 separate return ports. My T connector showed some restriction when using both heavy braking and turning , this will cause unwanted feedback in both the peddle and steering wheel. I run the duel return can, although I did fab the second input myself. you can buy them already done this way.

Last edited by pauldana; Apr 1, 2019 at 10:19 PM.