vacuum booster hell

[84conversion]

I recently converted my hot air car to a 87 w/ 212 212 cam. I also converted the brakes to a vacuum power booster. I have a good pedal at idle but the minute i get on it and then try to brake the pedal is hard till i get to idle again. I used a used unit from a elcamino .I think the booster is too small(its really thin and about a 12in diameter.If anyone has a idea please help , my patience is running low.. Thanks

 

[davidf]

Get yourself a rebuilt wagner booster for an 87 Regal V8. It is a dual diaphram. I pd. around $115.00.

 

[ericttype]

I recently converted my hot air car to a 87 w/ 212 212 cam. I also converted the brakes to a vacuum power booster. I have a good pedal at idle but the minute i get on it and then try to brake the pedal is hard till i get to idle again. I used a used unit from a elcamino .I think the booster is too small(its really thin and about a 12in diameter.If anyone has a idea please help , my patience is running low.. Thanks

the check valve at booster that the hose goes on this is a one way valve and if its bad your booster will not hold vacuum. i did the same conversion and have the same cam as you and my brakes are great, where do you have the vacuum line running?

 

[smokin87]

the check valve at booster that the hose goes on this is a one way valve and if its bad your booster will not hold vacuum. i did the same conversion and have the same cam as you and my brakes are great, where do you have the vacuum line running?

ericttype sounds right on on this one. What you are describing is exactly what would happen if your check valve was stuck open, or if you didn't have one installed at all.

 

[ericttype]

ericttype sounds right on on this one. What you are describing is exactly what would happen if your check valve was stuck open, or if you didn't have one installed at all.

yep been working on cars for 25+ years and seen it all and then some lol

 

[84conversion]

Thanks i just checked the one way valve at the booster and i checked the vac with my snap on vac gauge and its at 20hg. i just noticed that the boosters leaking at a just the right pedal position its enough of a vac drop. I am a 20year veteran tech, but im very new to these great cars... Thank you for you time and direction i am going to change the booster and add a additional brass one way valve

 

[84conversion]

Plus its a single diaphram booster to small

 

[jdpolzin]

Put your hydrobooster back on the car and have the best braking power you can get for these cars. I would never go from a Hydroboost to a vac.

 

[charlief1]

^^^ What he said. The vac system is lighter but the vac system needs some help. Get a vac tank to aid it as well.