hydroboost issues

[latrucker]

Hoping someone can lead me into the right direction. I replaced my hydroboost bracket from angled to staight offset. Once I put it back together and bleed the HB and the master cylinder i have spongy pedal. So much so that it wont even depress the brake light switch to turn the brake lights on. Yet it stops fine. Obviously i have air trapped somewhere just dont know where. Can the hydroboost make a pedal feel mushy and lite or would it have to be the mastercylinder. Bled the brakes 3 times but nothing changes and the steering doesnt whine so i guessing it doesnt have air on the hydroboost side. Any help is appreciated, thanks.

 

[catfan]

Hoping someone can lead me into the right direction. I replaced my hydroboost bracket from angled to staight offset. Once I put it back together and bleed the HB and the master cylinder i have spongy pedal. So much so that it wont even depress the brake light switch to turn the brake lights on. Yet it stops fine. Obviously i have air trapped somewhere just dont know where. Can the hydroboost make a pedal feel mushy and lite or would it have to be the mastercylinder. Bled the brakes 3 times but nothing changes and the steering doesnt whine so i guessing it doesnt have air on the hydroboost side. Any help is appreciated, thanks.

The brake light is a different issue, do you have my inline bracket from Ebay?

 

[bchesley]

Do you have the little plastic washer that goes on the pedal with the brake light switch? If you don't have the washer in the right spot it will not depress the switch correctly. The proper location for the washer in between the switch against the rod that pushes your HB. Hope that makes sense. I can take a photo if not.

 

[latrucker]

catfan its actually you bracket from ebay. Got it all mounted up, came out great. Problem I am having is the pedal is so lite that it doesnt have enough pressure to compress the spring on the brake light switch. I can squeeze it with my hand and it lights up. Im thinking air in the MC but i have bled it 3 times and nothing changed.

 

[latrucker]

Do you have the little plastic washer that goes on the pedal with the brake light switch? If you don't have the washer in the right spot it will not depress the switch correctly. The proper location for the washer in between the switch against the rod that pushes your HB. Hope that makes sense. I can take a photo if not.

Photo would be great if its not too much trouble. Thanks

 

[gr8scott]

What size bore is your MC? I tried a 1" bore master and it felt exactly as you described. Went to a 1 1/8" bore and problem solved.

 

[latrucker]

What size bore is your MC? I tried a 1" bore master and it felt exactly as you described. Went to a 1 1/8" bore and problem solved.

Mine is the 1" bore, its a 77 corvette MC. It worked fine on the other bracket before switching over so I assume it has to be air somewhere.

 

[catfan]

catfan its actually you bracket from ebay. Got it all mounted up, came out great. Problem I am having is the pedal is so lite that it doesnt have enough pressure to compress the spring on the brake light switch. I can squeeze it with my hand and it lights up. Im thinking air in the MC but i have bled it 3 times and nothing changed.

Sometimes I have the push rod too thin and the lights won't work. I always send a new push rod if that happens.

 

[latrucker]

Sometimes I have the push rod too thin and the lights won't work. I always send a new push rod if that happens.

Looks like that is the issue that I'm having. Not enough material on the end of the pushrod where it contacts the switch.

 

[jmhend]

catfan its actually you bracket from ebay. Got it all mounted up, came out great. Problem I am having is the pedal is so lite that it doesnt have enough pressure to compress the spring on the brake light switch. I can squeeze it with my hand and it lights up. Im thinking air in the MC but i have bled it 3 times and nothing changed.

That is my favorite hydroboost bracket. Following to see how you fix the brake light issue.

Sent from my SM-N960U using Tapatalk

 

[latrucker]

That is my favorite hydroboost bracket. Following to see how you fix the brake light issue.

Sent from my SM-N960U using Tapatalk

Works great, with a 351W and tall heads you can't get the drivers side valve cover off with the angled bracket. The offset bracket solved that problem. It's a nice piece for sure.

 

[Digger556]

Do you have a picture of the linkage?


I saw one of those in person and the linkage gave the pedal a different motion ratio and made it feel light.

 

[gr8scott]

Here's a picture of my linkage. If it changes the motion ratio, its negligible. My pedal does not feel light and squishy, but I do run a 1.125" bore master.

 

[latrucker]

Here's a picture of my linkage. If it changes the motion ratio, its negligible. My pedal does not feel light and squishy, but I do run a 1.125" bore master.

I don't think my problem has anything to do with the linkage. If I mash the brakes in gravel only the front will lock up. Pretty sure I have air in the rear somewheres. Looks like brake lights are a manufacturing defect in the pushrod.

 

[toddz69]

Mine is the 1" bore, its a 77 corvette MC. It worked fine on the other bracket before switching over so I assume it has to be air somewhere.

The 77 Corvette master should be 1 1/8" bore.

Todd Z.

 

[latrucker]

The 77 Corvette master should be 1 1/8" bore.

Todd Z.

Your correct, it's 1-1/8.

 

[NAK]

Do you need to bleed the power steering reservoir?

 

[gr8scott]

Also, in case you didn't already know, with these Corvette masters, the forward facing reservoir is for the front brakes, and the rear reservoir for the rear brakes.

 

[latrucker]

Also, in case you didn't already know, with these Corvette masters, the forward facing reservoir is for the front brakes, and the rear reservoir for the rear brakes.

That's the way mine is plumbed. The proportioning valve goes on the rear, correct? By the looks of it I have everything correctly installed. When I get time I'm going to bleed the brakes again and the HB, have a feeling I have air trapped somewhere. On gravel if I lock up the brakes only the front locks up. Should all 4 wheels be locking?

 

[catfan]

Looks like that is the issue that I'm having. Not enough material on the end of the pushrod where it contacts the switch.

I'll send you a new push rod Monday.