Brakes on 1971 K20 Cheyenne - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Murphy IRE · 10-31-2009, 10:59 AM

Just picked this up. We knew it needed work on the brakes. I'm the 3rd owner. It would would stop (soft), but it wouldn't lock up. The previous owner said he replaced the master cyclinder and other parts. The flex hoses are very old and showed their age. So I started to take them off. I was able to get them off the front calipers ( only one busted nuckle), but I can't get the connections to break at the steel line connections. I can hardly see the connections on the front let alone reach them. The rear is just being stubborn. The shoulders on gone on one of the flange nuts, so I'm down to using vise grips. I'm just about empty on the the 1st can of PB blaster. Any suggestions?

jsbgump · 11-01-2009, 10:18 AM

Welcome to the board from Texas

**70cst** · 11-09-2009, 11:45 AM

Murphy IRE ... Glad to have you on board. If you haven't posted your question on the 67-72 messsage forum please do so and you should be able to get your answer.

Again welcome ....

Murphy IRE · 01-03-2010, 11:56 AM

I finally found one of the major problems. A vacuum leak on a couple of hoses. I was robbing the vacuum boost. Also, because of the PO not discovering this they had the carb all wrong (too lean) and the choke all screwed up. As a result, the rpm's were too high! Because the PO installed a 7700R4 with a big torque converter, the thing was always pullling. Now that we got the tach working and set the idle correctly, the brakes are working much better. They are are few things to readjust but... Wow, so much better!

Things done,
New rotors, new drums (make sure you have all the right measurements - there are several that will go on, but they don't work), new calipers, new pads, new WC, new flex brake lines.

Hope this helps

10-31-2009, 10:59 AM	#1
Murphy IRE Registered User Join Date: Oct 2009 Location: South Denver Metro, CO Posts: 385	Brakes on 1971 K20 Cheyenne Just picked this up. We knew it needed work on the brakes. I'm the 3rd owner. It would would stop (soft), but it wouldn't lock up. The previous owner said he replaced the master cyclinder and other parts. The flex hoses are very old and showed their age. So I started to take them off. I was able to get them off the front calipers ( only one busted nuckle), but I can't get the connections to break at the steel line connections. I can hardly see the connections on the front let alone reach them. The rear is just being stubborn. The shoulders on gone on one of the flange nuts, so I'm down to using vise grips. I'm just about empty on the the 1st can of PB blaster. Any suggestions?

11-01-2009, 10:18 AM	#2
jsbgump Gone Fishing Join Date: Aug 2005 Location: Fort Worth, Texas 76135 Posts: 12,361	Re: Brakes on 1971 K20 Cheyenne Welcome to the board from Texas __________________ 68 Chevy Short Fleetside LSX Swap Under Way 3.73 posi 2.5/4 drop Frame of resto has been started 2022 Hyundai Tucson Limited 2019 Chevy Traverse Redline Edition Wifes Ride Build Thread http://67-72chevytrucks.com/vboard/s...=1#post3483616

11-09-2009, 11:45 AM	#3
70cst Senior Member Join Date: Feb 2001 Location: New Madison, Ohio Posts: 21,373	Re: Brakes on 1971 K20 Cheyenne Murphy IRE ... Glad to have you on board. If you haven't posted your question on the 67-72 messsage forum please do so and you should be able to get your answer. Again welcome .... __________________ A husband can be right...or...A husband can be happy. 67-72 Chevy and GMC Trucks...The Classic Truck for the Classic Folk. 1970 CST Two tone green, 402BB, 400 Automatic, Tach, Buckets, AC, AM-FM, Tilt, GM CB, GM 8 Tract, LWB, etc JOHN 17:3...The better side of "LIFE" Remember: Everyday is a good day...Some are just gooder!

01-03-2010, 11:56 AM	#4
Murphy IRE Registered User Join Date: Oct 2009 Location: South Denver Metro, CO Posts: 385	Re: Brakes on 1971 K20 Cheyenne I finally found one of the major problems. A vacuum leak on a couple of hoses. I was robbing the vacuum boost. Also, because of the PO not discovering this they had the carb all wrong (too lean) and the choke all screwed up. As a result, the rpm's were too high! Because the PO installed a 7700R4 with a big torque converter, the thing was always pullling. Now that we got the tach working and set the idle correctly, the brakes are working much better. They are are few things to readjust but... Wow, so much better! Things done, New rotors, new drums (make sure you have all the right measurements - there are several that will go on, but they don't work), new calipers, new pads, new WC, new flex brake lines. Hope this helps



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