66 k20 - Page 3 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**jdl71** · 09-30-2018, 03:27 PM

And what a shocker, something doesn’t jive. The wheel cylinders are 1” and 1/4, not 1” and 1/8” like the fronts, or like is listed in the fsm. Not really an issue I guess they weren’t pitted and the cups are still pretty supple. Gave it a quick hone and run through the parts washer so I will probably just put them back together. The drums are another matter, the machined surface measures about 12.5”. Once again referencing the manual, 1.25 wheel cylinders came on p30 and c30 with 13” brakes. Is it possible these drums have wore down half an inch?

**jdl71** · 09-30-2018, 03:31 PM

A second look gives me a 12.25 in measurement which makes even less sense. There’s a pretty good ridge in the middle all the way around so I know these have wear. I know the tape measure doesn’t look centered but it is. Am I measuring this the correct way?

**jdl71** · 09-30-2018, 06:35 PM

What is this and what’s its purpose? It was on the inside of the drum.

**jdl71** · 09-30-2018, 06:37 PM

And finally is there any reason to go past this point and remove the backing plate? Is there another seal behind there?

1972RedNeck · 09-30-2018, 07:54 PM

Quote:

Originally Posted by jdl71

What is this and what’s its purpose? It was on the inside of the drum.

I think it is to keep any oil off the brakes if the wheel seal were to leak.

Quote:

Originally Posted by jdl71

And finally is there any reason to go past this point and remove the backing plate? Is there another seal behind there?

No and no, unless you want to clean it up and paint it.

**jdl71** · 09-30-2018, 08:52 PM

Thanks!

**aotte1** · 09-30-2018, 10:17 PM

In post #54 you ask about a seal. On a 66’ C20, with Eaton HO 52 axle rear their is a cork seal. I am planning to use some “Right Stuff” on the outside of this, to seal it. My 64 C20, with same axle, had a seal, not sure of the marerial, it was in bad shape. Will try to find photos. Planning to take one apart this week.

Les

**aotte1** · 09-30-2018, 10:30 PM

Front brake hoses

A brake hose speciality company made mine. Will try to remember to get you the company name and address. They may have been located in MI. If I forget please ask me for it.

Les

**Captainfab** · 09-30-2018, 11:49 PM

I would say that your drums are worn about .250". You will likely have to make the change to 14 bolt drums since those HO52 drums are no longer available.

**jdl71** · 10-01-2018, 10:34 AM

Quote:

Originally Posted by Captainfab

I would say that your drums are worn about .250". You will likely have to make the change to 14 bolt drums since those HO52 drums are no longer available.

Rockauto actually does list them.

**LostMy65** · 10-01-2018, 10:50 AM

Looks good.

Lokin4AReason · 10-01-2018, 01:11 PM

nice progress ...

**jdl71** · 10-01-2018, 06:39 PM

Quote:

Originally Posted by aotte1

In post #54 you ask about a seal. On a 66’ C20, with Eaton HO 52 axle rear their is a cork seal. I am planning to use some “Right Stuff” on the outside of this, to seal it. My 64 C20, with same axle, had a seal, not sure of the marerial, it was in bad shape. Will try to find photos. Planning to take one apart this week.

Les

If you're referring to a seal between the backing plate and axle tube, I'm not going that far right now. I found the wheel seal that goes in the hub locally.

**jdl71** · 10-01-2018, 06:40 PM

Quote:

Originally Posted by aotte1

Front brake hoses

A brake hose speciality company made mine. Will try to remember to get you the company name and address. They may have been located in MI. If I forget please ask me for it.

Les

I've got something cobbled together for now, but I would be interested in that. Thanks!

**jdl71** · 10-01-2018, 08:20 PM

These are the shoes that were on the left rear. Yes they are both the same.

**72cs20** · 10-01-2018, 08:22 PM

Quote:

Originally Posted by jdl71

Next, brakes. What a nightmare. I knew going in that some of the stuff would be hard to find. I did not know how hard. Hoses do not exist anymore. This is the solution myself and my napa guy could come up with:

Jdl71,

The steering arm and brake hose set up on your truck are quite different from mine. Does your K20 have the rare HD Dana 44?

**jdl71** · 10-01-2018, 08:25 PM

Quote:

Originally Posted by 72cs20

Jdl71,

The steering arm and brake hose set up on your truck are quite different from mine. Does your K20 have the rare HD Dana 44?

Unfortunately, yes.

**Captainfab** · 10-02-2018, 12:26 AM

I stand corrected. I was under the impression that the drums were no longer available.

Quote:

Originally Posted by jdl71

Rockauto actually does list them.

raylube · 10-02-2018, 12:53 AM

I will soon be pulling my k20 with Eaton rear and may need drums also. Just wondering if you have verified those rock auto drum will work. Shoes are 2 inches wide and these drums spec is 2.43

**jdl71** · 10-02-2018, 08:10 AM

Quote:

Originally Posted by raylube

I will soon be pulling my k20 with Eaton rear and may need drums also. Just wondering if you have verified those rock auto drum will work. Shoes are 2 inches wide and these drums spec is 2.43

It’s supposed to be here tomorrow. I saw that also so I measured the old drum and found that it’s over 2” wide on friction surface so it should work.

**aotte1** · 10-02-2018, 11:02 PM

Custom Brake Hoses- please see photos. Have used them, no issues, on 64’ K10.

Les

**jdl71** · 10-04-2018, 06:53 PM

Quote:

Originally Posted by aotte1

Custom Brake Hoses- please see photos. Have used them, no issues, on 64’ K10.

Les

Thank you Les.

**jdl71** · 10-04-2018, 07:23 PM

Quote:

Originally Posted by raylube

I will soon be pulling my k20 with Eaton rear and may need drums also. Just wondering if you have verified those rock auto drum will work. Shoes are 2 inches wide and these drums spec is 2.43

Haven’t actually put it on, but looks pretty good to me.

Lokin4AReason · 10-05-2018, 12:13 PM

looks about the same with it being a little wider in width ( as in width of the brake pad )

**jdl71** · 10-05-2018, 01:49 PM

Quote:

Originally Posted by Lokin4AReason

looks about the same with it being a little wider in width ( as in width of the brake pad )

It does look like that but i measured and it’s within 1/8 of an inch at most.

09-30-2018, 03:27 PM	#51
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 And what a shocker, something doesn’t jive. The wheel cylinders are 1” and 1/4, not 1” and 1/8” like the fronts, or like is listed in the fsm. Not really an issue I guess they weren’t pitted and the cups are still pretty supple. Gave it a quick hone and run through the parts washer so I will probably just put them back together. The drums are another matter, the machined surface measures about 12.5”. Once again referencing the manual, 1.25 wheel cylinders came on p30 and c30 with 13” brakes. Is it possible these drums have wore down half an inch? Attached Images __________________ Psalm 23 64 C10 66 K20

09-30-2018, 03:31 PM	#52
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 A second look gives me a 12.25 in measurement which makes even less sense. There’s a pretty good ridge in the middle all the way around so I know these have wear. I know the tape measure doesn’t look centered but it is. Am I measuring this the correct way? Attached Images __________________ Psalm 23 64 C10 66 K20

09-30-2018, 06:35 PM	#53
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 What is this and what’s its purpose? It was on the inside of the drum. Attached Images __________________ Psalm 23 64 C10 66 K20

09-30-2018, 08:52 PM	#56
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 Thanks! __________________ Psalm 23 64 C10 66 K20

09-30-2018, 10:17 PM	#57
aotte1 Senior Member Join Date: Oct 2013 Location: lousiville Ky Posts: 2,637	Re: 66 k20 In post #54 you ask about a seal. On a 66’ C20, with Eaton HO 52 axle rear their is a cork seal. I am planning to use some “Right Stuff” on the outside of this, to seal it. My 64 C20, with same axle, had a seal, not sure of the marerial, it was in bad shape. Will try to find photos. Planning to take one apart this week. Les

09-30-2018, 06:37 PM	#54
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 And finally is there any reason to go past this point and remove the backing plate? Is there another seal behind there? Attached Images __________________ Psalm 23 64 C10 66 K20

09-30-2018, 10:30 PM	#58
aotte1 Senior Member Join Date: Oct 2013 Location: lousiville Ky Posts: 2,637	Re: 66 k20 Front brake hoses A brake hose speciality company made mine. Will try to remember to get you the company name and address. They may have been located in MI. If I forget please ask me for it. Les

09-30-2018, 11:49 PM	#59
Captainfab 60-66 Nut Join Date: Mar 2007 Location: Coeur d'Alene, Idaho Posts: 23,246	Re: 66 k20 I would say that your drums are worn about .250". You will likely have to make the change to 14 bolt drums since those HO52 drums are no longer available. __________________ Power Steering Box Adapter Plates For Sale HERE Power Brake Booster Adapter Brackets For Sale '63-'66 HERE and '67-'72 HERE and '60-'62 HERE and "60-'62 with clutch HERE Rear Disc Brake Brackets For Sale. Impala SS calipers HERE Camaro Calipers HERE D52 Calipers HERE 6 Lug HERE Hydroboost Mounting Plates HERE

10-01-2018, 10:50 AM	#61
LostMy65 But Found Her 25yrs Later! Join Date: Oct 2010 Location: Oregon City, Oregon Posts: 10,460	Re: 66 k20 Looks good. __________________ I lost my 65 - Found it 25 years later: http://67-72chevytrucks.com/vboard/s...d.php?t=426650 66 C20 Service Truck: http://67-72chevytrucks.com/vboard/s...d.php?t=428035

10-01-2018, 01:11 PM	#62
Lokin4AReason Registered User Join Date: Oct 2014 Location: a beer can .. Posts: 924	Re: 66 k20 nice progress ... __________________ dont want to hear excuses, i want to hear solution(s)

10-01-2018, 08:20 PM	#65
jdl71 Senior Member Join Date: Oct 2012 Location: Eldon, MO Posts: 1,753	Re: 66 k20 These are the shoes that were on the left rear. Yes they are both the same. Attached Images __________________ Psalm 23 64 C10 66 K20

10-02-2018, 12:53 AM	#69
raylube Registered User Join Date: Jan 2012 Location: Preston Idaho Posts: 276	Re: 66 k20 I will soon be pulling my k20 with Eaton rear and may need drums also. Just wondering if you have verified those rock auto drum will work. Shoes are 2 inches wide and these drums spec is 2.43

10-02-2018, 11:02 PM	#71
aotte1 Senior Member Join Date: Oct 2013 Location: lousiville Ky Posts: 2,637	Re: 66 k20 Custom Brake Hoses- please see photos. Have used them, no issues, on 64’ K10. Les Attached Images

10-05-2018, 12:13 PM	#74
Lokin4AReason Registered User Join Date: Oct 2014 Location: a beer can .. Posts: 924	Re: 66 k20 looks about the same with it being a little wider in width ( as in width of the brake pad ) __________________ dont want to hear excuses, i want to hear solution(s)

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