Stopping After the swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sluggy · 10-21-2018, 05:08 PM

I have an ls3/6l80 combo in my 62 C20. Currently i have discs up font and drums in the rear.
Because I still have the original 62 front suspension, I have used Early classics C20 to C10 conversion spindles, and their disc kit on the front end. Running a vacuum assist master cylinder. I changed the rear end to a 12 bolt and am just running the stock drums on the rear.
I have had a couple of close calls where she just keeps rolling !! So I feel like I need better anchors.
Id be interested to hear what others are using ?

ls1nova71 · 10-22-2018, 10:41 AM

The set up you have should be pretty decent, but if it's not working right, are you sure its fully bled? If so, what size of vacuum booster are you running? I had a 7" dual diaphragm booster on my car that everybody said was the thing to use and it was terrible. I switched to a Hydroboost and its way better. Might be something to consider, although I don't know how hard they are to come by in New Zealand.

BR3W CITY · 10-22-2018, 11:02 AM

I'm running a hydroboost setup with Wilwood's up front, and am in the process of converting my 12bolt to run D52's out back via Captain Fab's setup.

Even on disc/drum my truck stops pretty damn flat in a hurry, plenty to lock em up if needed.

I did randomly find out this weekend that my truck had a Wilwood 2lb anti-drainback valve in the front lines...never knew that before. Supposedly it helps with calipers that draw-back too far when the master is mounted low. Not sure if its helping me, but I'm keeping it in.

**truckdude239** · 10-23-2018, 10:17 AM

Im rocking the stock non power brakes on my 71 disc /drum and it stops just fine something isnt right with your set up

Custom 68 · 10-23-2018, 12:08 PM

Brew, which master cylinder did you go with on your setup. I am using one from a hydro boost tahoe and think it is too large of diameter. I am looking to swap down a size. I believe mine is 1.25 diameter bore. I think I need a 1.125
Thanks
Dave

BR3W CITY · 10-23-2018, 01:23 PM

I'm using the master that came off the hydroboost donor. ~96 astro

sluggy · 10-23-2018, 03:34 PM

Pedal feels solid, but i will give it another bleed anyway, booster is a 9" single diaphragm. There is no way I can get this to lock up though. I am running 20" detroit steel wheels, these things are heavy - approaching 55lbs per rim plus the tyre, Im pretty sure that doesnt help much. Ive got some 15" rims that i will try on it to see if that makes muh difference.

verdell · 10-23-2018, 03:50 PM

Quote:

Originally Posted by sluggy

I have an ls3/6l80 combo in my 62 C20. Currently i have discs up font and drums in the rear.
Because I still have the original 62 front suspension, I have used Early classics C20 to C10 conversion spindles, and their disc kit on the front end. Running a vacuum assist master cylinder. I changed the rear end to a 12 bolt and am just running the stock drums on the rear.
I have had a couple of close calls where she just keeps rolling !! So I feel like I need better anchors.
Id be interested to hear what others are using ?

I have CPP dropped spindles, '75 1/2 ton mc, dual diaphragm booster and a 65 12 bolt drum rear with no issues. Are you certain your torque converter is unlocking?

Custom 68 · 10-23-2018, 03:54 PM

Quote:

Originally Posted by BR3W CITY

I'm using the master that came off the hydroboost donor. ~96 astro

Thanks I may give one a try.
Dave

**1971Stepside** · 10-23-2018, 05:23 PM

Dave, I have one off an astro you can have. It is missing a cap off the big reservoir.

Custom 68 · 10-24-2018, 10:29 AM

Thanks Shannon, we do need to get together.
Dave

sluggy · 10-27-2018, 12:37 AM

Quote:

Originally Posted by verdell

I have CPP dropped spindles, '75 1/2 ton mc, dual diaphragm booster and a 65 12 bolt drum rear with no issues. Are you certain your torque converter is unlocking?

I think that is the issue. It feels like its driving through the brakes. I'll check the wiring to the trans and make sure I have it right.
Thanks for the suggestion !!

72MARIO · 10-27-2018, 12:46 AM

Quote:

Originally Posted by sluggy

Pedal feels solid, but i will give it another bleed anyway, booster is a 9" single diaphragm. There is no way I can get this to lock up though. I am running 20" detroit steel wheels, these things are heavy - approaching 55lbs per rim plus the tyre, Im pretty sure that doesnt help much. Ive got some 15" rims that i will try on it to see if that makes muh difference.

I am interested how much of.a diffirence the 15" rims make in stopping. I have been looking at the Detroit wheels but the weight was my concern..

**1970 CST Short Wide** · 10-27-2018, 10:34 PM

Quote:

Originally Posted by BR3W CITY

I'm running a hydroboost setup with Wilwood's up front, and am in the process of converting my 12bolt to run D52's out back via Captain Fab's setup.

Even on disc/drum my truck stops pretty damn flat in a hurry, plenty to lock em up if needed.

I did randomly find out this weekend that my truck had a Wilwood 2lb anti-drainback valve in the front lines...never knew that before. Supposedly it helps with calipers that draw-back too far when the master is mounted low. Not sure if its helping me, but I'm keeping it in.

I’m still running 15” wheels. Will Wilwoods fit or do you have larger diameter wheels?

BR3W CITY · 10-28-2018, 11:52 AM

That really depends on the wheel. My M/T front wheels clear them, and my Holeshot rears clear them, but my older Diamond's would be uncomfortably close.

Custom 68 · 10-29-2018, 10:32 AM

Quote:

Originally Posted by 1970 CST Short Wide

I’m still running 15” wheels. Will Wilwoods fit or do you have larger diameter wheels?

I have the Wilwoods D52 replacement on the front and they will not clear my old 15 inch aluminum wheels. It is close but there is a slight rubbing.
I have converted to an aftermarket spindle so that may have a little affect?

bigmoe · 12-18-2018, 11:03 PM

Quote:

Originally Posted by sluggy

I think that is the issue. It feels like its driving through the brakes. I'll check the wiring to the trans and make sure I have it right.
Thanks for the suggestion !!

Sluggy did you solve your braking problem? Would you be able to throw it into neutral and brake, to rule out the torque converter?

10-21-2018, 05:08 PM	#1
sluggy Registered User Join Date: Mar 2017 Location: Auckland, NZ Posts: 27	Stopping After the swap I have an ls3/6l80 combo in my 62 C20. Currently i have discs up font and drums in the rear. Because I still have the original 62 front suspension, I have used Early classics C20 to C10 conversion spindles, and their disc kit on the front end. Running a vacuum assist master cylinder. I changed the rear end to a 12 bolt and am just running the stock drums on the rear. I have had a couple of close calls where she just keeps rolling !! So I feel like I need better anchors. Id be interested to hear what others are using ?

10-22-2018, 10:41 AM	#2
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,118	Re: Stopping After the swap The set up you have should be pretty decent, but if it's not working right, are you sure its fully bled? If so, what size of vacuum booster are you running? I had a 7" dual diaphragm booster on my car that everybody said was the thing to use and it was terrible. I switched to a Hydroboost and its way better. Might be something to consider, although I don't know how hard they are to come by in New Zealand. __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

10-22-2018, 11:02 AM	#3
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Stopping After the swap I'm running a hydroboost setup with Wilwood's up front, and am in the process of converting my 12bolt to run D52's out back via Captain Fab's setup. Even on disc/drum my truck stops pretty damn flat in a hurry, plenty to lock em up if needed. I did randomly find out this weekend that my truck had a Wilwood 2lb anti-drainback valve in the front lines...never knew that before. Supposedly it helps with calipers that draw-back too far when the master is mounted low. Not sure if its helping me, but I'm keeping it in. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

10-23-2018, 10:17 AM	#4
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,237	Re: Stopping After the swap Im rocking the stock non power brakes on my 71 disc /drum and it stops just fine something isnt right with your set up __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube

10-23-2018, 12:08 PM	#5
Custom 68 Registered User Join Date: Nov 2001 Location: Springfield, MO Posts: 2,939	Re: Stopping After the swap Brew, which master cylinder did you go with on your setup. I am using one from a hydro boost tahoe and think it is too large of diameter. I am looking to swap down a size. I believe mine is 1.25 diameter bore. I think I need a 1.125 Thanks Dave __________________ Dave 1968 Custom Chevy with turbo charged 5.3 gen III 4l80e swap 1967-71 GMC 3/4 ton long step 4x4 (not sure what year exactly?) "A good friend will bail you out of jail...but a true friend will be sitting next to you saying "that was frekin awesome". "If it doesn't fit force it...If it breaks then it needed to be replaced anyway!"

10-23-2018, 01:23 PM	#6
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Stopping After the swap I'm using the master that came off the hydroboost donor. ~96 astro __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

10-23-2018, 03:34 PM	#7
sluggy Registered User Join Date: Mar 2017 Location: Auckland, NZ Posts: 27	Re: Stopping After the swap Pedal feels solid, but i will give it another bleed anyway, booster is a 9" single diaphragm. There is no way I can get this to lock up though. I am running 20" detroit steel wheels, these things are heavy - approaching 55lbs per rim plus the tyre, Im pretty sure that doesnt help much. Ive got some 15" rims that i will try on it to see if that makes muh difference.

10-23-2018, 05:23 PM	#10
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Re: Stopping After the swap Dave, I have one off an astro you can have. It is missing a cap off the big reservoir. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

10-24-2018, 10:29 AM	#11
Custom 68 Registered User Join Date: Nov 2001 Location: Springfield, MO Posts: 2,939	Re: Stopping After the swap Thanks Shannon, we do need to get together. Dave __________________ Dave 1968 Custom Chevy with turbo charged 5.3 gen III 4l80e swap 1967-71 GMC 3/4 ton long step 4x4 (not sure what year exactly?) "A good friend will bail you out of jail...but a true friend will be sitting next to you saying "that was frekin awesome". "If it doesn't fit force it...If it breaks then it needed to be replaced anyway!"

10-28-2018, 11:52 AM	#15
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: Stopping After the swap That really depends on the wheel. My M/T front wheels clear them, and my Holeshot rears clear them, but my older Diamond's would be uncomfortably close. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.