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-   -   1970 Blazer disk brake conversion (https://67-72chevytrucks.com/vboard/showthread.php?t=385614)

chevyross 02-07-2010 10:09 PM

1970 Blazer disk brake conversion
 
I'm planning to convert my front drum brakes on my 1970 Blazer to disk brakes. What parts will I need to locate? Can I use my steering knuckles on the Dana axle? Thanks.

bigdon-70blazer 02-07-2010 11:01 PM

Re: 1970 Blazer disk brake conversion
 
Good question!

SeventyOne 02-08-2010 12:56 AM

Re: 1970 Blazer disk brake conversion
 
Do you have an open or closed knuckle? Can you see the axle u-joint?

If it's open, I would go to a junkyard and get the knuckles out from a 71-91 (or later even?) 1/2 ton chevy to start. It will give you the spindle, outer axle shaft (if it's different), caliper brackets, and caliper cores.

Then get a new rotor and either rebuild or replace the calipers, install new pads, new bearings.

Probably something I'm leaving out but that ought to get you close.

SeventyOne 02-08-2010 01:01 AM

Re: 1970 Blazer disk brake conversion
 
Ok with a little research you should have a closed knuckle axle. I am not sure if it is as easy as I wrote above or if your inner knuckles will even allow an open style outer knuckle to bolt up to it. Can you post a pic?

drunkbus 02-08-2010 02:40 PM

Re: 1970 Blazer disk brake conversion
 
Why not just replace the whole front end with one that already has disc brakes? You should be able to pick up a disc brake dana 44 front for around $75-$100 and it would be a lot easier.

pound41 02-08-2010 03:02 PM

Re: 1970 Blazer disk brake conversion
 
In my 70 we went with the complete front end
My 70 had power brakes Drum/Drum on it . When we replaced the front end the brakes were soft to me. I changed the prop valve and the M/C. The fitting on the drum brake lines are different than the drums. I had to search fittings at the plumbing warehouse

SeventyOne 02-08-2010 03:41 PM

Re: 1970 Blazer disk brake conversion
 
Quote:

Originally Posted by drunkbus (Post 3788101)
Why not just replace the whole front end with one that already has disc brakes? You should be able to pick up a disc brake dana 44 front for around $75-$100 and it would be a lot easier.

So long as the gear ratio is the same. I would still recommend redoing the brakes and bearings - would probably cost the same. and maybe even axle seals depending on condition.

Something I read while doing some quick research was that the steering arm/outer knuckle changed in 1971 so this swap might affect the steering geometry.

too much stuff 02-08-2010 05:50 PM

Re: 1970 Blazer disk brake conversion
 
Quote:

Originally Posted by SeventyOne (Post 3787374)
Do you have an open or closed knuckle? Can you see the axle u-joint?

If it's open, I would go to a junkyard and get the knuckles out from a 71-91 (or later even?) 1/2 ton chevy to start. It will give you the spindle, outer axle shaft (if it's different), caliper brackets, and caliper cores.

Then get a new rotor and either rebuild or replace the calipers, install new pads, new bearings.

Probably something I'm leaving out but that ought to get you close.

If original yet, it should have drum brakes with an open knuckle. One year only for that. I would do as suggested and just find a donor front end from 71 up into the late 70s. I believe it is basically a bolt in procedure. Make sure the gear ratio is the same...

pound41 02-08-2010 07:14 PM

Re: 1970 Blazer disk brake conversion
 
Quote:

Originally Posted by SeventyOne (Post 3788213)
So long as the gear ratio is the same. I would still recommend redoing the brakes and bearings - would probably cost the same. and maybe even axle seals depending on condition.

Something I read while doing some quick research was that the steering arm/outer knuckle changed in 1971 so this swap might affect the steering geometry.

My 70 blazer is out of comission for floor pan replacement. During the short time I drove it I swore to my Dad that the steering/turning radius was different than my 71 blazer
It seemed to me that it did not turn as well in one direction. I really noticed it in turning into parking spaces etc.I will have to research that steering arm/outer knuckle change
Thanks

SeventyOne 02-08-2010 07:57 PM

Re: 1970 Blazer disk brake conversion
 
Quote:

Originally Posted by pound41 (Post 3788576)
My 70 blazer is out of comission for floor pan replacement. During the short time I drove it I swore to my Dad that the steering/turning radius was different than my 71 blazer
It seemed to me that it did not turn as well in one direction. I really noticed it in turning into parking spaces etc.I will have to research that steering arm/outer knuckle change
Thanks

I read that 71 was the first year for the 3 hole steering arm/knuckle. This seems to be backed up because if you buy lifts for a fist gen Blazer it should ask if you need the lifted steering arm or drop pitman.

Anyone with a stock 70 axle want to take a pic?

cvalcore 02-09-2010 12:25 AM

Re: 1970 Blazer disk brake conversion
 
it would be ten easier just to swap the axle out you can buy them for $100 bucks all day long i no because i have had several of them and had a very hard time selling them in the past. i just gave one away not to long ago out of a 72 blazer to a guy that was doing the same thing

Livrat 02-09-2010 12:35 AM

Re: 1970 Blazer disk brake conversion
 
Quote:

Originally Posted by chevyross (Post 3786969)
I'm planning to convert my front drum brakes on my 1970 Blazer to disk brakes. What parts will I need to locate? Can I use my steering knuckles on the Dana axle? Thanks.

1970 Blazer is a one year only open knuckle drum brake Dana 44 front axle..
Yes you can use your existing steering knuckles,, all you need are 71 up spindles, hubs. rotors, backing plates, 71/72 disc brake master cylinder and proportioning valve and all the front brake lines.
It is easier to find a donor axle and just swap the entire assembly.. but if you cannot find one with the correct gear ratio then just swap from the spindles out..


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