FE-FC Holden Discussion Forum

Technical Board => Restoration Help => Topic started by: Fraze on February 03, 2017, 11:50:05 AM



Title: Ribbed brake drums
Post by: Fraze on February 03, 2017, 11:50:05 AM
Question for the Gurus : Were  FC brake drums ribbed? The drums on my FC are all ribbed and I have four spare drums (obtained from two separate sources) which are also ribbed. Or are all of these after market. I also have an FB which has ribbed drums per the FC ones (but 1/4" wider). Are these aftermarket as well? Next question - I have heard that EH drums interchange with FB - EK without mods or changes - is that fact? Thanks, Fraze


Title: Re: Ribbed brake drums
Post by: Errol62 on February 03, 2017, 12:32:46 PM
Hi Fraze
Read the recent thread titled FE/FC Drums started on 1/2/17 by RET. These are Repco after market and improve cooling to reduce fade.

I wonder how common these are.

Cheers
Clay


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Title: Re: Ribbed brake drums
Post by: Errol62 on February 03, 2017, 12:33:45 PM
Also recent discussion on the FB EK site


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Title: Re: Ribbed brake drums
Post by: ardiesse on February 03, 2017, 02:28:52 PM
Fraze,

All the FC drums I have seen so far have been ribbed, but that's not to say that all FC drums are ribbed.
On the other hand, FB/EK drums come in both ribbed and plain varieties.  Usually the ribbed drums ended up on the front and the plain drums on the rear if you had a vehicle with one pair of each.

I think you're right about backwards compatibility of EJ/EH drums onto FB/EK brakes, but I'm trying to scrounge up an EJ/EH drum to compare its internal dimensions with an FB/EK drum.

The Repco drums were finned "the other way" compared with Holden drums.

Rob


Title: Re: Ribbed brake drums
Post by: ardiesse on February 03, 2017, 04:12:22 PM
Fraze (again),

Errol62 has just measured the inside depth of an FB/EK drum and an EJ/EH drum, and it's the same: 2-9/16".
Which means that EJ/EH drums are a straight swap onto FB/EK brakes.

Rob


Title: Re: Ribbed brake drums
Post by: DJ on February 03, 2017, 04:47:25 PM
Rob,
On the other hand, FB/EK drums come in both ribbed and plain varieties.  Usually the ribbed drums ended up on the front and the plain drums on the rear if you had a vehicle with one pair of each.

Which is what I had on my FC when I bought it a very long time ago. To my untrained eye, there was no other obvious difference in dimension or shape.

The Repco drums were finned "the other way" compared with Holden drums.

Just had a look at one trying to image what you mean here. The very edge of the open side forms the first fin on mine. I assume they are Holden.
For Repco, do you mean the first valley was machined on the edge of the open side?



Title: Re: Ribbed brake drums
Post by: mcl1959 on February 03, 2017, 05:35:46 PM
All FE FC drums are ribbed, but the costruction is a turned rim welded onto a pressed steel flange.
The REPCO heavy duty drums are machined from a solid single piece I think. The flange is thicker and they are much heavier than a normal drum.

Ken


Title: Re: Ribbed brake drums
Post by: fcwrangler on February 03, 2017, 06:39:28 PM
The difference between the FB/EK drum and the EJ on drum only minor, but could cause problems with the rims. The FB has the same dimples as the FC face where the EJ drums have a flat face. I will do a test fit tomorrow on the FB Vans front end with the EJ drums I have for the FC. I'm also with Ken, I have only seen ribbed drums on the FE/FC, I have seen drums that have ribs across the drum not around. I also have an old PBR drum which ribs around the drum but has a flat mounting face not raised or dimpled
Jim


Title: Re: Ribbed brake drums
Post by: DJ on February 03, 2017, 06:51:20 PM
I have seen drums that have ribs across the drum not around.
I haven't seen or heard of these ones.
With a huge temperature range & the valley running that way, were they prone to cracking?


Title: Re: Ribbed brake drums
Post by: fcwrangler on February 03, 2017, 07:35:33 PM
There was a set or a pair? on eBay late last year for around $300 from memory.
Jim


Title: Re: Ribbed brake drums
Post by: customFC on February 04, 2017, 04:38:32 PM
(http://img.photobucket.com/albums/v608/customfc2/FEFC%20instr/Repco-drum.jpg)
Regards
Alex


Title: Re: Ribbed brake drums
Post by: DJ on February 04, 2017, 04:48:25 PM
Thanks Alex. I get it now. Cleaver design but what a monster!  :o


Title: Ribbed brake drums
Post by: Errol62 on February 04, 2017, 06:50:54 PM
This is a drum I got with a complete rear axle I took off an EH wagon at Kadina in 1988. The face is not flat. (https://uploads.tapatalk-cdn.com/20170204/729abc35cf58f52cf377385f5dfebf6d.jpg)
It doesn't have the raised bits between the stud holes like the FE EK ones do though. I guess that's what was meant by flat hey.

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Title: Re: Ribbed brake drums
Post by: Fraze on February 05, 2017, 08:40:59 AM
Thanks for all of the replies. Looks like all FE FC brake drums were ribbed and most FBs. Eks seem to have had plain drums. It also seems that EH drums will fit FB-EK ------BUT it also seems that you can't use standard FE - EK wheels with the EH drums!!!! A friend is hunting out an old EH drum for me so that I can physically check for myself but it doesn't look good. Cheers, Fraze


Title: Re: Ribbed brake drums
Post by: RET on February 05, 2017, 01:29:54 PM
BUT it also seems that you can't use standard FE - EK wheels with the EH drums!

I've been exploring this further, and I don't believe that's totally true.

The Master Parts Catalogue shows a single part number 7408888 for all wheels from FE up to and including EH. (They also show the same part number for the hub and the bolts all the way through, which is why I think the assertion about mismatched drums and wheels causing drum warp is all bullshit.)

However, as was the case with the introduction of the FE where the sedan came first and the other models followed, so it was with the HD, and there was a run-on of EH utes and vans for about 4 months. It looks like these had HD brakes, so it would be true to say that you can't use FE-EK wheels on EH drums if the drums are from a late (Feb-July 1965) ute or van, for the same reason you have to use HD/HR wheels with HD/HR brakes.

Happy to be corrected by later-model gurus, of course.


Title: Re: Ribbed brake drums
Post by: Errol62 on February 05, 2017, 02:15:27 PM
I reckon you could be on to something there RET and it is the HD HR style wheels which cause binding on the early drums.


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Title: Re: Ribbed brake drums
Post by: Dr_Terry on February 06, 2017, 03:22:02 PM
I reckon you could be on to something there RET and it is the HD HR style wheels which cause binding on the early drums.


It's actually it's the other way around. As RET has said all FE to EH wheels (except for those off '65 EH utes & vans with HD brakes) are interchangeable. There are minor changes though, like the size of the valve hole in early rims & whether they are arc-welded, spot-welded or riveted. These wheels will fit FE to EH. If you fit them over the wider HR drums, the drum will be badly distorted. 

HD/HR wheels however, will fit all back to FE.

Dr Terry


Title: Re: Ribbed brake drums
Post by: Errol62 on February 06, 2017, 06:04:47 PM
What you say makes sense to me Dr Terry however a very knowledgable member of the FB EK forum insists that he has had an issue with EH rims causing binding on FB EK drums.


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Title: Re: Ribbed brake drums
Post by: RET on February 06, 2017, 07:14:46 PM
Well I reckon his EH drums were the wider HD type. They should be the same dimensions as FB-EK drums, so if they're not, that seems the most likely reason.


Title: Re: Ribbed brake drums
Post by: Dr_Terry on February 07, 2017, 03:04:49 PM
The only instance that I have seen any issue with steel rims fitting over FB/EK drums is with non-original rims which do not have divots to clear the small 'bumps' between the stud holes. The face of the FB/EK drums is not flat like those EJ onwards.

A good example would be the later aftermarket steel rims which are made for caravans & trailers etc. These will fit EJ-HR & Torana, but will damage early drums where these 'bumps' exists.

Dr Terry


Title: Re: Ribbed brake drums
Post by: Errol62 on February 07, 2017, 04:43:33 PM
Tend to agree Ret, Dr Terry.
Fraze,
General consensus is EJ EH drums can be slipped on to stock FB EK brake setup. The parallel radial ribs were stock on FE FC and most FB.
Cheers
Clay


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Title: Re: Ribbed brake drums
Post by: Fraze on February 08, 2017, 07:25:43 AM
Well it looks like I can use the EH drums with standard steel wheels on my FB ute but before I buy them, I will try an old eh drum which a friend is loaning me just to be sure. Thanks for all the replies, cheers, Fraze


Title: Re: Ribbed brake drums
Post by: Errol62 on February 08, 2017, 09:31:29 AM
That's the best idea. Look forward to hearing the outcome.


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Title: Re: Ribbed brake drums
Post by: fcwrangler on February 08, 2017, 04:45:44 PM
Fraze, they do fit, I did a test fit on the weekend. I have an old rusty FB van and a EJ front end that I am fitting to my FC, I took the drums of the EJ and fitted them onto the FB front end and bolted the rims back on with no problems.
Regards, Jim


Title: Re: Ribbed brake drums
Post by: Fraze on February 16, 2017, 07:28:28 AM
I just fitted a set of new repro EH brake drums to an FB, no issues at all,  ;D. And in studying the whole situation I can't see any reason why you would not be able to use EH brake drums on an FE FC either. The only thing would be that the narrower FE FC brake linings wouldn't wipe the whole surface of the EH drum, but I cannot see that that would matter! Cheers, Fraze


Title: Re: Ribbed brake drums
Post by: fcwrangler on February 16, 2017, 07:38:50 AM
Fraze, they don't fit because of the extra width in the drum, when you bolt them onto the hub they bind on the backing plate.
Jim


Title: Re: Ribbed brake drums
Post by: Errol62 on February 16, 2017, 07:53:38 AM
Possibly the EH drums could be machined down for clearance?


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Title: Re: Ribbed brake drums
Post by: RET on February 16, 2017, 08:29:44 PM
Yes, that's the solution proposed by another club member. In fact he's done exactly that to an FC he previously owned - bought EH repro drums and had 6mm taken off the drum edge. They fitted and worked perfectly. I passed this suggestion onto the original requestor that prompted the other thread (http://forum.fefcholden.club/index.php?topic=26449), and am waiting to hear the result.

cheers
RET


Title: Re: Ribbed brake drums
Post by: Fraze on February 17, 2017, 07:27:33 AM
Interesting comments about machining the extra width off the EH drums. Although I haven't actually tried EH drums on an FC yet so I might be going off half cocked BUT....... The extra width of the EH drums is on the mounting flange side of the drum and therefore is inside the well of the wheel!!! When I put the drums together on the bench and measure from the mounting flange to the outside rim of the drum the FC, FB and EH drums all measure the same (within a mm ) Certainly not 6mm!!! Over the next couple of days I will try an EH drum on my FC, Fraze


Title: Re: Ribbed brake drums
Post by: Errol62 on February 17, 2017, 08:18:23 AM
I think the difference will be in the FC backing plate Fraze.


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