Pre-war (up to 1942) Nose diving when braking

[axleech24]

Hi All,

I have nose diving situation when braking with medium to firm pressure on the pedal in the 40 Lasalle.  Would this be a weak front coil spring problem or do the lever action shocks need to be looked at?  As far as know the springs have never been replaced.

Thanks, Grayle

[TJ Hopland]

Are the rear brakes in good working order and adjusted?   

[Cadillac Jack 82]

brakes not balanced/adjusted properly.

[axleech24]

Brakes are good. They dont pull to a side at all. I flushed the lines and installed new wheel cylinders on all 4 corners last summer.  I adjusted the drums using the feeler gauge as outlined in the manual. The only thing I did do was replace the 2 front wheel cylinders that were 1 3/32 bore with Buick wheel cylinders that are 1 1/8 bore. Just a small increase in size.

[The Tassie Devil(le)]

I know it isn't much, but even that much increase will definitely give an unbalanced braking.

The Springs control the downward pressure, and the Shocks the rebound.

Bruce.

[TJ Hopland]

Doesn't sound like much but that could easily be it.   Its not just a 1/32 bigger since its a circle and you are adding that to the outside so area wise its more than you think. 

It may be worth checking the clearance on the back again just to make sure they are still where they should be.  If it was new stuff they wear pretty quick while the shoes conform to the drum size. 

If you have one of those IR temp guns you can also take readings after a test drive to see how even things are and that the rears are doing some work.

[The Tassie Devil(le)]

The rears are there to basically keep the car on the straight and narrow when hard braking.   Too much rear bias, rears will lock up, and the back of the car will try and overtake the front depending on how viscous the road camber is.   One reason why factory rear brake linings last so much longer than the fronts.

Bruce.

[axleech24]

Sounds like my 84 year old springs and shocks are not the issue here.  I had trouble finding new 1 3/32 wheel cylinders.  I will have to send them out for sleeving to restore the proper balance again.  Next time I take it out for a drive, I will check the temps between front and back. Thanks for all the help.

[TJ Hopland]

Back is always going to be doing less work but if there is pretty much no heat back there or an imbalance side to side that will warrant a closer look at the adjustment back there.

[Brad Ipsen CLC #737]

I have several 40 Cadillac & LaSalle's and as far as I remember all have front cylinders with 1-1/8.  No problem with that.  If you haven't done shocks and if they haven't been done previously that would be a good thing to do in any case.

[z3skybolt]

Sounds like my 84 year old springs and shocks are not the issue here.  I had trouble finding new 1 3/32 wheel cylinders.  I will have to send them out for sleeving to restore the proper balance again.  Next time I take it out for a drive, I will check the temps between front and back. Thanks for all the help.

I bought complete, new, brake systems and rebuilt hydraulic shocks for my 1940 LaSalle from Cadillacpartsltd@yahoo.co. They have about 5,000 miles on them and work beautifully.  I recently bought an idler arm and set of universal joints from Michael.  Over the years he has had everything I have sought.   The springs on my LaSalle were tired after 94,000 miles.  I had new coil springs made for the front end and new leaf springs for the rear.  Along with the replacement shocks I enjoy a ride that rivals/exceeds a modern sedan. Good luck.

Bob R.

[tcom2027]

Good morning,

Your coil springs most likely fatigued. However first check the oil levels in the shocks. Add hydraulic oil if necessary. Then bleed by leaving the plug(s) out and pushing down on the body, letting it return slowly. THis will take time. Following that check your ride height and compare it to the specs in the Body manual. The specs for the springs are there too. Replace the coils if necessary.

There is a company in Kansas, Coil Springs Specialties, that makes springs for "classics". They are popular in The Tri Chevy community. I don't know if they make springs for prewar cars. You may also try Eaton. The '40 LaSalle front coils cross with the '41 61 Series I
believe. If Kanter is still around, they ay still sell front springs for the LaSalles.
.
I replaced the front coils and had Apple rebuild the shocks on my '41 coupe. The results were amazing. Rebuilt Houdaille lever shocks are still available from Apple Hydraulics for around $250 each.

Hope this helps.

tony

 

[tcom2027]

I bought complete, new, brake systems and rebuilt hydraulic shocks for my 1940 LaSalle from Cadillacpartsltd@yahoo.co. They have about 5,000 miles on them and work beautifully.  I recently bought an idler arm and set of universal joints from Michael.  Over the years he has had everything I have sought.   The springs on my LaSalle were tired after 94,000 miles.  I had new coil springs made for the front end and new leaf springs for the rear.  Along with the replacement shocks I enjoy a ride that rivals/exceeds a modern sedan. Good luck.

Bob R.

I agree, After I replaced the shocks and springs on my '41 coupe it rode better than my then four year old Seville. I had 1 1/8' wheel cylinders in my Coupe and '40 60 Special. No braking problems.

CadillacPartsLtd is a fantastic source. 

tony

[39LaSalleDriver]

Add myself to the list of those who swear by Apple Hydraulics and Eaton Detroit Springs. Had them redo my shocks and springs all around and can't say enough about how good they both were to deal with. Not to mention how satisfied I was with the work that they did. My 39 LaSalle rides like a dream now. Also can speak to the quality of Cadillac Parts Ltd. I've ordered a few items from him and couldn't be happier.

[z3skybolt]

Good morning,

Your coil springs most likely fatigued. However first check the oil levels in the shocks. Add hydraulic oil if necessary. Then bleed by leaving the plug(s) out and pushing down on the body, letting it return slowly. THis will take time. Following that check your ride height and compare it to the specs in the Body manual. The specs for the springs are there too. Replace the coils if necessary.

There is a company in Kansas, Coil Springs Specialties, that makes springs for "classics". They are popular in The Tri Chevy community. I don't know if they make springs for prewar cars. You may also try Eaton. The '40 LaSalle front coils cross with the '41 61 Series I
believe. If Kanter is still around, they ay still sell front springs for the LaSalles.
.
I replaced the front coils and had Apple rebuild the shocks on my '41 coupe. The results were amazing. Rebuilt Houdaille lever shocks are still available from Apple Hydraulics for around $250 each.

Hope this helps.





 Tony,
I bought my coil springs from COIL SPRINGS SPECIALTY.  St. Louis Spring made my leaf springs for $400.00 less than Eaton wanted.  St. Louis Spring still had the spec sheet for the 1940 LaSalle.  He said the paper was browned and wrinkled but still readable.

Maybe a new moto is in order: RIDES LIKE A LASALLE!!

Bob R.

 

[axleech24]

I like the direction this post has headed.  I'm trying my best to keep this car on the road and reading these replies has helped me take the necessary steps to keep it roadworthy and handle and steering like it should.. The car wanders, the steering is loose and going over bumps that don't affect my daily driver Saturn, really affect this old Lasalle. It still has bias ply tires on it, so that could be an issue as well.  Thanks for all the replies!

[Ralph Messina CLC 4937]

FWIW, The larger 1 1/8" diameter wheel cylinders would apply 6% more pressure on the shoes than the stock 1 3/32", all things being equal.