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MG Midget and Sprite Technical - Front Coil Springs

Now this is interesting...

Today, I tried to use my floor jack to raise the front of my 1972 RWA but it would not fit UNDER the anti-roll bar. This car has been out of winter storage for about a month or so and this was the first time I tried to lift the front end to grease it...

Very strange since my garage floor has not changed and my 10 year old Sears floor jack has not gained weight (or height...). Are my front springs aging or failing? My question is: when stock front coil springs weaken ( or age ) do they actually compress more? Is my car sinking or is the ground rising?

For the last few years or so - I have thought of upgrading the front springs but from what I have read – uprated coil springs often (always?) lower the front of the vehicle. Based on the number of times my front exhaust pipe has bounced off speed bumps in parking lots – I don’t want to lower the car any further – in fact, my short term goal is to be able to slide my floor jack under the car from the front side to perform periodic maintenance, etc.

Any experience out there with front coil springs that get shorter with age?
Is this even possible?

Thanks in advance for any replies.
And no – I don’t really want to buy a new aluminum racing or low profile jack...

Mike P.
Upstate New York


Mike Pelone

Try checking your tyre pressures.

I used a scissor jack to jack the front up a couple of inches, then I can get a trolley under the x-member... or sometimes I drive the front onto low wooden blocks to give clearance for the trolley.

Sounds to me like your front is ~correct height.

A
Anthony

I thought this was normal, and I always have to give the front a little heave upward to push the jack in after a rest period. Just one hand under the bumper - nothing arduous.

It always goes back to normal after the suspension has had a workout on the road.
Nick

Ditto to what Nick said.
Jeremy Cogman

If the car was reversed into the garage and the brakes applied to slow then stop it, this would have the effect of diving front end making it sit lower than it otherwise would. This may account for the difference.
robnrrugby

put a length of wood across the chasis rails infront of the roll bar and jack it up so the wheels are just off the ground, then lower again. Your jack will now clear the roll bar.
Nick

Well, I guess I'm going with Nick's solution since I already cut a piece of 2"x4" in the garage to use in front on the roll bar...

On a totally unrelated note, while the front of the car was jacked up, I installed a set of SpeedBleeders ( modified caliper bleed screws with a spring loaded ball bearing inside the bleed screw )...should have bought a set of these bad boys about 15 years ago...just a few pumps of the brake pedal and presto - no more need for a Lovely Assistant...which is a good thing since the wife is tired of pushing the brake pedal up & down based on my verbal instructions...

Thanks for the comments

MSP
Mike Pelone

Great!

We over in the UK have more of a challenge getting hold of those SpeedBleeders. I'd love a set........jealous.
Rich Amos (1330cc Blaze Red '72)

http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MCYCLE&pcode=GDRBN704SB

if someone wants to let me know the size that would be grand! I have recon calipers, so it might even be metric??
Nick

Beat me to the link, I got some the other week from them.

K Harris

Nick - www.speedbleeder.com

Jordan Gibson

3/8 at the front 1/4 rears
K Harris

Errr...is this the point where I tell you they cost $7/each plus $5 shipping....

Sorry - could not resist...
Mike Pelone

Well, on the subject of bleeding...

I threw away my old eezibleed because it decided to blow it's seals once, so yesterday I bought a new one yesterday..

I used the Eezibleed and was met with just the same problem, even at around 10PSI!!! The 2 tubes which exit the lid of it were leaking air around their exit holes massively, right from out-the-box. Really annoying to buy something which fundamentally doesn't do what it says on the tin!

Have caked the lid in sealant to see if thatll stop the leakage......

But for now, spongeyyyy brakes!
Rich Amos (1330cc Blaze Red '72)

Rich Eezibleed NEEDS very tight connections to stop such leaks

I use a fibre washer each side of the connection or a rubber O ring each side to ensure a great seal.

waste of time and money if you cannot achieve airtightness there though

but mine IS airtight and I am very happy with it, had it more than twenty years now! (many more...)

Bill

My Eezibleed leaked out of the box too unless *really* tight. Needless to say after a couple of uses the cap disintegrated due to the strain.

I contacted gunson and they sent me a new cap/hose assembly FOC next day. This one seals well without excessive tightening and works fine.
Jordan Gibson

It wasn't the cap, it was the dual pipes going into the bottle cap. Leaked right from the start. Sealed it, but the seal burst(!).

So, I got my beautiful assistant to help, did it the old way and now have beautifully responsive brakes again!

The mintex rear shoes are a vast improvement, too.

End to a saga.
Rich Amos (1330cc Blaze Red '72)

Mike
A couple of years ago I took the springs out of my 71 and test them on a calibrated load device. They were within a pound of the rated value. If I remember correctly they are rated at 270 lb/inch. They tested to 269. If spring are fabricated from quality metal, they won't loose much over time.

Ken
Ken

Mike, my car gets lower after a prolonged rest mostly due to the tires losing pressure and also going slightly flat spotted. As already said, use the 2X4 to start the car up and it will settle high enough to get a jack under it after that.
Bill Young

Ken,

They shouldn't lose their rate over time unless due to rusting reducing the diameter. The stiffness of the material won't change although the spring might settle a bit in use but that is not a change in the material stiffness.
David Billington

David
A slight bit of rust looks worse than it actually is. As small layer of metal that rust looks rather thick, but if you removed the rust, I would wager that you would find an insignificant change in the spring coil diameter. I've seen that in piping where the plant worries about the intergrity of the pressure boundry....we measure wall thichness and find no change.

Ken
Ken

This thread was discussed between 27/06/2008 and 04/07/2008

MG Midget and Sprite Technical index

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