MG Sports Cars

Being new to the MG seen I want to know more about HTOB for a T5 trans. I can't seem to find any MG sites that have these parts. Can you just get them from any auto parts store? and how does it mount up to the clutch/pressure plate? Any links on this subject would be helpful.

This is a great example of when the magnificent "search" function of the BritishV8 website really can be your best friend. Type a keyword like "HTOB" into the little beige box at page top, and press the little gold button that says "Google", then presto you get linked to all sorts of articles that mention these horrible pieces of junk...

But, since I know one particularly good photo off hand, I'll post it here:



You'll notice that the HTOB doesn't actually mount up to either the clutch or the pressure plate. Rather, it mounts to the transmission, and doesn't contact the pressure plate until you stomp on the pedal. It never contacts the clutch at all, because the clutch is sandwiched up between the pressure plate and flywheel.

There are many reasons to avoid HTOB's if you can. One reason is that they're expensive. Another is that they're easily damaged by hyperextension. (You'll almost certainly need to install a pedal stop to avoid this.) A third reason is that the fittings have historically tended to leak and you can't do anything about it without pulling the engine and/or transmission. (Improvements have supposedly been made by some of the vendors... This was the biggest complaint against McLoed brand HTOB's.) Getting the adjustment just right can be tricky. My biggest complaint about my old Tilton HTOB (now removed and recently sold on eBay for an obscenely high price) was that it didn't quite have enough travel - so even when carefully adjusted, I felt it was operating near it's limit.

Use of HTOB's on OEM installations is pretty rare. I believe this article shows a couple photos of a Ford HTOB: [www.britishv8.org]
Therefore, you probably won't find a HTOB for T5 at your local auto parts store - but you should find them online from most any of the major performance parts houses.

If I were you, however, I'd look for "pull type" slave cylinders that can be mounted next to the transmission, as shown below (from Jack Pease's HIWD article... Use the search box for more references.) Multiple brands are available. The niftiest ones mount with a single bolt through a Heim joint centered at their tail end (so that they automatically pivot to keep the pulling force centered on the piston/seals.)

Ooops. I almost forgot to mention that HTOB's can be a real pain in the butt to bleed.

Of course, some of us have had good luck with them. I think using high quality silicon brake fluid helped (not the cheap stuff).

Jim

D&D Facbrication most likely can supply the HTOB for you.

Brian McCullough sells a complete kit including the SS hose that connects directly to the master cylinder.. I bought one and am pleased with it.


[bmcautos.com]

Whenever you can do business with BritishV8 vendor sponsors, that's a real good thing.

Brian helps keep this website growing!

MAN I can't thank you enough for the info from all of you guys. Being new to British V8 I didn't know about the search tool. I thought it was just a google thing. I am thinking and trying to come up with the best cost effective way to make a V6 conversion. I have already price a Trans and motor from a local J-yard and for $800 with the wiring and ECM. But I am also looking into just getting the MG back on the road and just install the original motor (if I can find one that is cheap). I like the thought of adding the V6. Just getting a game plan together before I start and study the install before I jump. Planning will be the key to this project. Thanks.

Quote:

Of course, some of us have had good luck with them. I think using high quality silicon brake fluid helped

I've had no problems with my McCleod HTOB, either. I use Castrol LMA brake fluid in mine, though.

I like the idea better of using the slave cylinder to pull the clutch. It would probably fell better on the foot, being able to feel the clutch move that is. Great idea.Moderator Wrote:
-------------------------------------------------------
> This is a great example of when the magnificent
> "search" function of the BritishV8 website really
> can be your best friend. Type a keyword like
> "HTOB" into the little beige box at page top, and
> press the little gold button that says "Google",
> then presto you get linked to all sorts of
> articles that mention these horrible pieces of
> junk...
>
> But, since I know one particularly good photo off
> hand, I'll post it here:
>
> [www.britishv8.org]-
> ZG.jpg
>
> You'll notice that the HTOB doesn't actually mount
> up to either the clutch or the pressure plate.
> Rather, it mounts to the transmission, and doesn't
> contact the pressure plate until you stomp on the
> pedal. It never contacts the clutch at all,
> because the clutch is sandwiched up between the
> pressure plate and flywheel.
>
> There are many reasons to avoid HTOB's if you can.
> One reason is that they're expensive. Another is
> that they're easily damaged by hyperextension.
> (You'll almost certainly need to install a pedal
> stop to avoid this.) A third reason is that the
> fittings have historically tended to leak and you
> can't do anything about it without pulling the
> engine and/or transmission. (Improvements have
> supposedly been made by some of the vendors...
> This was the biggest complaint against McLoed
> brand HTOB's.) Getting the adjustment just right
> can be tricky. My biggest complaint about my old
> Tilton HTOB (now removed and recently sold on eBay
> for an obscenely high price) was that it didn't
> quite have enough travel - so even when carefully
> adjusted, I felt it was operating near it's
> limit.
>
> Use of HTOB's on OEM installations is pretty rare.
> I believe this article shows a couple photos of a
> Ford HTOB:
> [www.britishv8.org]
> Therefore, you probably won't find a HTOB for T5
> at your local auto parts store - but you should
> find them online from most any of the major
> performance parts houses.
>
> If I were you, however, I'd look for "pull type"
> slave cylinders that can be mounted next to the
> transmission, as shown below (from Jack Pease's
> HIWD article... Use the search box for more
> references.) Multiple brands are available. The
> niftiest ones mount with a single bolt through a
> Heim joint centered at their tail end (so that
> they automatically pivot to keep the pulling force
> centered on the piston/seals.)
>
> [www.britishv8.org].
> jpg

I couldn't tell any difference in the feel from external to internal cylinder, but I wish I'd had the internal one before I put a box under the gas pedal for clearance of the external one. It does make a handy heel rest though.

Jim

I have to agree with Curtis.

The HTOB is great when you can't fit anything else. I understand that there are specific conversions where they are necessary.

But if there is any other way, use it. Why add expense, maintenance hassle and further expense (like pulling the engine to get at the blasted thing), and possible problems with operation unless you absolutely have to? If you can just make up a custom bracket to carry a conventional slave unit attached to the bellhousing, that's the way to go.

I did that, using attachment to the stock (left side) Camaro bellhousing flange, but if that isn't possible beause of clearance issues, perhaps something else like the one pictured by Curtis would be.